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Key Largo

$129+ Cheap flights from Seattle (SEA) to Key Largo, FL

This is the cheapest one-way flight price found by a Cheapflights user in the last 72 hours by searching for a flight departing on 4/15. Fares are subject to change and may not be available on all flights or dates of travel.
SEA — MIA
Apr 18 — Apr 251
Sat 4/18
Sat 4/25
1 adult, Economy
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Cheapflights Tip: The best prices from Seattle/Tacoma Intl to Key Largo are usually found in September or October, booked 56 days in advance, depart on a Tuesday or Thursday and return on a Wednesday

Cheap flight deals from Seattle to Key Largo

Cheapest flights from Seattle to Key Largo
Explore the most affordable flight options available from Seattle to Key Largo. Find the lowest fares from popular airlines and budget airlines, with prices last updated on March 19, 2026.

This Delta deal was found by Cheapflights users on 3/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 5/47:15 am
SEA
-
MIA
Nonstop5h 56m
Delta
Wed 5/136:05 pm
MIA
-
SEA
Nonstop6h 50m
Delta
Deal found 3/16$199
This Kiwi.com deal was found by Cheapflights users on 3/17. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 4/207:12 pm
SEA
-
MIA
1 stop30h 53m
Frontier
Tue 4/287:00 am
MIA
-
SEA
1 stop29h 27m
Frontier
Deal found 3/17$202
This Kiwi.com deal was found by Cheapflights users on 3/17. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Kiwi.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 4/207:12 pm
SEA
-
MIA
1 stop30h 53m
Frontier
Wed 4/297:00 am
MIA
-
SEA
1 stop29h 27m
Frontier
Deal found 3/17$207
This Delta deal was found by Cheapflights users on 3/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 4/197:15 am
SEA
-
MIA
Nonstop5h 56m
Delta
Tue 4/287:10 am
MIA
-
SEA
1 stop10h 41m
Delta
Deal found 3/15$208
This Delta deal was found by Cheapflights users on 3/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Delta is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sat 5/25:55 pm
SEA
-
MIA
1 stop8h 32m
Delta
Wed 5/65:25 pm
MIA
-
SEA
Nonstop6h 40m
Delta
Deal found 3/16$209
This Frontier deal was found by Cheapflights users on 3/15. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 4/199:54 pm
SEA
-
MIA
1 stop30h 28m
Frontier
Tue 4/287:00 am
MIA
-
SEA
1 stop29h 27m
Frontier
Deal found 3/15$214
This CheapOair deal was found by Cheapflights users on 3/17. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure CheapOair is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 4/1312:42 pm
SEA
-
MIA
1 stop14h 07m
Frontier
Wed 4/157:00 am
MIA
-
SEA
1 stop29h 27m
Frontier
Deal found 3/17$215
This Frontier deal was found by Cheapflights users on 3/16. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 5/14:20 pm
SEA
-
MIA
1 stop9h 45m
Frontier
Fri 5/159:41 pm
MIA
-
SEA
1 stop15h 41m
Frontier
Deal found 3/16$220
This Frontier deal was found by Cheapflights users on 3/17. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure Frontier is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 5/14:20 pm
SEA
-
MIA
1 stop9h 45m
Frontier
Fri 5/89:41 pm
MIA
-
SEA
1 stop15h 41m
Frontier
Deal found 3/17$221

Find flight deals from Seattle to Key Largo

Keep the following information in mind while searching for Seattle to Key Largo flight deals. Data was last updated March 19, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$199
(Delta)

One-way from

$129
(Delta)

Popular in

December

Cheapest in

September

Average price

$348
Provider with most accurate pricing for Seattle/Tacoma Intl-Miami flight deals.
Search Deals
Provider most trusted by Cheapflights users for Seattle/Tacoma Intl-Miami flights.
Search Deals
From Seattle/Tacoma Intl to Key Largo
Search Deals
One-way flight from Seattle/Tacoma Intl to Key Largo
Search Deals
Highest demand for flights based on searches. 13% potential increase in price ($53 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 4% potential price decrease ($15 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in March 2026
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from Seattle to Key Largo that fit within your specific budget. Explore options based on user searches and filter the results based on your desired price range. Find flights that match your budget for a cost-effective journey. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated March 19, 2026.
Use the filters below to find and compare flights from Seattle to Key Largo that are best for you.

Fly from

Fly to

Route

Depart

Return

Price

Cheapest round-trip

SeattleMiami

SEA - MIA

SEAMIA

Seattle/Tacoma Intl

Wed 4/15

7:15 am-4:11 pm

Nonstop5h 56m

Miami

Tue 4/28

7:10 am-2:51 pm

1 stop10h 41m

$209

SeattleMiami

SEA - MIA

SEAMIA

Seattle/Tacoma Intl

Sat 4/18

8:30 am-7:40 pm

1 stop8h 10m

Miami

Thu 4/23

6:05 pm-12:05 am

1 stop9h 00m

$219

SeattleMiami

SEA - MIA

SEAMIA

Seattle/Tacoma Intl

Fri 5/8

7:50 am-4:50 pm

Nonstop6h 00m

Miami

Fri 5/15

8:10 am-4:53 pm

1 stop11h 43m

$278

SeattleMiami

SEA - MIA

SEAMIA

Seattle/Tacoma Intl

Tue 4/14

7:15 am-4:11 pm

Nonstop5h 56m

Miami

Tue 4/21

4:43 pm-10:05 pm

1 stop8h 22m

$308

SeattleMiami

SEA - MIA

SEAMIA

Seattle/Tacoma Intl

Tue 4/28

11:45 pm-11:55 am

1 stop9h 10m

Miami

Tue 5/5

6:40 am-12:45 pm

1 stop9h 05m

$328
Quickest round-trip

SeattleMiami

SEA - MIA

SEAMIA

Seattle/Tacoma Intl

Sat 4/18

7:15 am-4:11 pm

Nonstop5h 56m

Miami

Tue 4/21

5:25 pm-9:05 pm

Nonstop6h 40m

$328

SeattleMiami

SEA - MIA

SEAMIA

Seattle/Tacoma Intl

Mon 4/27

10:35 pm-2:27 pm

2 stops12h 52m

Miami

Wed 4/29

12:24 pm-7:00 pm

1 stop9h 36m

$361

SeattleMiami

SEA - MIA

SEAMIA

Seattle/Tacoma Intl

Wed 4/15

6:00 am-9:10 pm

2 stops12h 10m

Miami

Wed 4/22

1:25 pm-10:30 pm

2 stops12h 05m

$394

SeattleMiami

SEA - MIA

SEAMIA

Seattle/Tacoma Intl

Sat 5/2

5:45 am-8:20 pm

2 stops11h 35m

Miami

Sat 5/9

8:25 am-6:15 pm

2 stops12h 50m

$395

SeattleMiami

SEA - MIA

SEAMIA

Seattle/Tacoma Intl

Tue 4/21

4:10 pm-9:20 am

2 stops14h 10m

Miami

Wed 6/3

6:07 pm-9:55 pm

Nonstop6h 48m

$397

Flights are sorted by cheapest round-trip flights first.

Deals found on 3/14

Showing 1-10 of 23 resultsSorted by cheapest first
1
2
3

Best time to book a flight from Seattle to Key Largo

Have a flexible travel schedule? Discover the best time to fly to Key Largo from Seattle with our price prediction graph.
Estimated round-trip price
Rates are based on past data. Find the cheapest month and day to book your flight based on your travel requirements, then search for cheap deals.

Cheapflights Insights

Everything you need to know about your flight from Seattle to Key Largo

How far ahead should I book a flight from Seattle to Key Largo?

Use this chart to determine the optimal time to book a round-trip flight from Seattle to Key Largo. Price data was last updated on March 13, 2026.

The price you pay for your flight from Seattle to Key Largo may vary depending on when you book. For the best chance of a lower fare, look to book 56 days in advance of your trip. Fares are likely to increase a fortnight or so before your departure date.

What is the cheapest month to book a flight from Seattle to Key Largo?

Currently, November is the cheapest month in which you can book a flight from Seattle to Key Largo (average of $136). Flying from Seattle to Key Largo in December is currently the most expensive (average of $183). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

What is the cheapest time of day to fly from SEA to KE9?

Find hourly flight availability from Seattle to Key Largo. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated March 19, 2026.

When flying from Seattle to Key Largo, the time of day you decide to fly out makes little to no difference towards the overall price you’ll pay on tickets.

Weekly flight availability from Seattle to Key Largo

Explore weekly flight availability from Seattle to Key Largo. Discover flights operating on different days of the week, giving you the flexibility to choose a travel day that best fits your plans. Compare info to find the most convenient option for your journey. Data last updated March 19, 2026.

The most flights from SEA to KE9 are scheduled on a Wednesday (6 on average). You will have fewer flight options on Monday, which is when the least amount of flights are scheduled (3 on average).

Reviews of airlines servicing Key Largo

Get insights into the airlines that provide service to Key Largo. Read reviews, discover amenities, and learn about the overall travel experience offered by airlines. Use this information to make informed decisions when choosing an airline for your flight to Key Largo. Reviews last updated March 19, 2026.
See what other customers who have flown with Alaska Airlines,Delta, andHawaiian Airlines from Seattle to Key Largo have to say. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.
Alaska Airlines
7.9
Good
12,075 reviews

Crew

8.5

Food

7.0

Boarding

8.1

Overall

7.9

Entertainment

7.0

Comfort

7.8

Reviews

1 / 20
4.0
Okay

Anonymous,Dec 2025

SEA - MSY

I really got a lesson in upgrades. I let my seat get chosen . Both times a middle seat...on purpose ...even when we were not full. That's petty I sat behind the first class . They got more than 1 drink ...and a snack . .and the staff actually talked to them...behind a see thru shawl/sheet in the aisle....... You could see over the seats just fine and you could hear the voices just fine. But the sheet let You KNOW. Your not welcome here. For a moment I regretted not spending 300 dollars per seat so I could see a smile and eat a sandwhich and enjoy my seat . The married couple drank champain and laughed and flirted with each other. It looked so happy and care free MONEY really does buy happiness ..the hateful glares and sighs from my seat mates brought me back to reality I wasn't rich and I still had 2 hours left in this middle seat.
Alaska Airlines
7.9
Good
12,075 reviews
Alaska Airlines
7.9
Good
12,075 reviews

Crew

8.5

Food

7.0

Boarding

8.1

Overall

7.9

Entertainment

7.0

Comfort

7.8

Reviews

1 / 20
4.0
Okay

Anonymous,Dec 2025

SEA - MSY

I really got a lesson in upgrades. I let my seat get chosen . Both times a middle seat...on purpose ...even when we were not full. That's petty I sat behind the first class . They got more than 1 drink ...and a snack . .and the staff actually talked to them...behind a see thru shawl/sheet in the aisle....... You could see over the seats just fine and you could hear the voices just fine. But the sheet let You KNOW. Your not welcome here. For a moment I regretted not spending 300 dollars per seat so I could see a smile and eat a sandwhich and enjoy my seat . The married couple drank champain and laughed and flirted with each other. It looked so happy and care free MONEY really does buy happiness ..the hateful glares and sighs from my seat mates brought me back to reality I wasn't rich and I still had 2 hours left in this middle seat.
Delta
7.9
Good
8,300 reviews
Alaska Airlines
7.9
Good
12,075 reviews

Crew

8.5

Food

7.0

Boarding

8.1

Overall

7.9

Entertainment

7.0

Comfort

7.8

Reviews

1 / 20
4.0
Okay

Anonymous,Dec 2025

SEA - MSY

I really got a lesson in upgrades. I let my seat get chosen . Both times a middle seat...on purpose ...even when we were not full. That's petty I sat behind the first class . They got more than 1 drink ...and a snack . .and the staff actually talked to them...behind a see thru shawl/sheet in the aisle....... You could see over the seats just fine and you could hear the voices just fine. But the sheet let You KNOW. Your not welcome here. For a moment I regretted not spending 300 dollars per seat so I could see a smile and eat a sandwhich and enjoy my seat . The married couple drank champain and laughed and flirted with each other. It looked so happy and care free MONEY really does buy happiness ..the hateful glares and sighs from my seat mates brought me back to reality I wasn't rich and I still had 2 hours left in this middle seat.
Hawaiian Airlines
7.8
Good
2,841 reviews
Alaska Airlines
7.9
Good
12,075 reviews

Crew

8.5

Food

7.0

Boarding

8.1

Overall

7.9

Entertainment

7.0

Comfort

7.8

Reviews

1 / 20
4.0
Okay

Anonymous,Dec 2025

SEA - MSY

I really got a lesson in upgrades. I let my seat get chosen . Both times a middle seat...on purpose ...even when we were not full. That's petty I sat behind the first class . They got more than 1 drink ...and a snack . .and the staff actually talked to them...behind a see thru shawl/sheet in the aisle....... You could see over the seats just fine and you could hear the voices just fine. But the sheet let You KNOW. Your not welcome here. For a moment I regretted not spending 300 dollars per seat so I could see a smile and eat a sandwhich and enjoy my seat . The married couple drank champain and laughed and flirted with each other. It looked so happy and care free MONEY really does buy happiness ..the hateful glares and sighs from my seat mates brought me back to reality I wasn't rich and I still had 2 hours left in this middle seat.
American Airlines
7.1
Good
11,477 reviews
Alaska Airlines
7.9
Good
12,075 reviews

Crew

8.5

Food

7.0

Boarding

8.1

Overall

7.9

Entertainment

7.0

Comfort

7.8

Reviews

1 / 20
4.0
Okay

Anonymous,Dec 2025

SEA - MSY

I really got a lesson in upgrades. I let my seat get chosen . Both times a middle seat...on purpose ...even when we were not full. That's petty I sat behind the first class . They got more than 1 drink ...and a snack . .and the staff actually talked to them...behind a see thru shawl/sheet in the aisle....... You could see over the seats just fine and you could hear the voices just fine. But the sheet let You KNOW. Your not welcome here. For a moment I regretted not spending 300 dollars per seat so I could see a smile and eat a sandwhich and enjoy my seat . The married couple drank champain and laughed and flirted with each other. It looked so happy and care free MONEY really does buy happiness ..the hateful glares and sighs from my seat mates brought me back to reality I wasn't rich and I still had 2 hours left in this middle seat.
Frontier
5.7
Fair
3,024 reviews
Alaska Airlines
7.9
Good
12,075 reviews

Crew

8.5

Food

7.0

Boarding

8.1

Overall

7.9

Entertainment

7.0

Comfort

7.8

Reviews

1 / 20
4.0
Okay

Anonymous,Dec 2025

SEA - MSY

I really got a lesson in upgrades. I let my seat get chosen . Both times a middle seat...on purpose ...even when we were not full. That's petty I sat behind the first class . They got more than 1 drink ...and a snack . .and the staff actually talked to them...behind a see thru shawl/sheet in the aisle....... You could see over the seats just fine and you could hear the voices just fine. But the sheet let You KNOW. Your not welcome here. For a moment I regretted not spending 300 dollars per seat so I could see a smile and eat a sandwhich and enjoy my seat . The married couple drank champain and laughed and flirted with each other. It looked so happy and care free MONEY really does buy happiness ..the hateful glares and sighs from my seat mates brought me back to reality I wasn't rich and I still had 2 hours left in this middle seat.

Related info for your journey

Find useful and relevant information for your journey from Seattle to Key Largo. Access travel guides, tips, and recommendations to enhance your travel experience. Get information about local attractions, weather, transportation options, and more.

  • What airport do you fly from for flights from Seattle to Key Largo?

    Seattle/Tacoma Intl (SEA) is the airport you will fly out of if you book a flight from Seattle to Key Largo. You should not have trouble finding flights to Key Largo from Seattle/Tacoma Intl; the airport handles an average of 4 outbound flights to Key Largo per day. You should also have plenty of airline options to choose from since 10 airlines have flights from the Seattle airport to Key Largo. It is only a 11.4 mi journey to Seattle/Tacoma Intl (SEA) from Seattle’s city center.

  • How popular is this Seattle to Key Largo flight route?

    The Seattle/Tacoma Intl to Key Largo flight path was viewed by 47 users in the past month. Keep an eye out for changes in search interest prior to high and low season.

  • How long is the flight from Seattle to Key Largo?

    Departing from Seattle to Key Largo will take you 5h 56m. There are 2719 mi between Seattle and Key Largo. This flight may include one or multiple stops.

  • What are the cheapest airlines to fly from Seattle to Key Largo one-way?

    $105 is the cheapest one-way deal found within the past few days, from Frontier. You may also be able to find cheap deals on Spirit Airlines and Hawaiian Airlines, with prices starting from $114 and $118, respectively.

  • What are the most reliable airlines from Seattle to Key Largo?

    Before booking your flight to Key Largo from Seattle, check out the most reliable airlines to get you to your destination on time: Qatar Airways (91%), American Airlines (90%), Air Tahiti Nui( 82%).

  • What are the cheapest flights from Seattle to Key Largo?

    The cheapest flight price from Seattle to Key Largo is $109. On average you can expect to pay $744. The most popular route, (Seattle/Tacoma Intl - Miami), can usually be booked for $199.

  • Can I find deals for flights from Seattle to Key Largo that include hotel bookings?

    Yes. In addition to deals on Seattle to Key Largo flights, Cheapflights offers vacation packages that include both flights and hotel.

  • How can I find direct flights from Seattle to Key Largo?

    After entering your origin and destination, apply the non-stop filter on the search result page to find direct flights from Seattle to Key Largo.

  • Can I find deals for business class flights from Seattle to Key Largo?

    Yes. Cheapflights offers flight deals from Seattle to Key Largo by cabin class. In addition to browsing deals, you can also filter by cabin class on the search results page after making a search.

  • What is the cheapest month to book a flight from Seattle to Key Largo?

    Currently, November is the cheapest month in which you can book a flight from Seattle to Key Largo (average of $136). Flying from Seattle to Key Largo in December is currently the most expensive (average of $183). There are several factors that can impact the price of a flight, so comparing airlines, departure airports and flight times can provide users with more options.

See more FAQs

Browse thousands of different options on Cheapflights for your next trip

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Top 10 airlines flying from Seattle to Key Largo

Discover the top 10 airlines that operate flights from Seattle to Key Largo. Compare their services, reliability, and customer satisfaction ratings to choose the airline that best suits your travel preferences and needs. Over the last 7 days, Cheapflights users made 2,558,603 searches. Data last updated March 19, 2026.
AirlineCheapestAverageFlexibilityOn-time
Hawaiian AirlinesCheapest$118Average$294FlexibilityNo cancel feeOn-time85%
Spirit AirlinesCheapest$134Average$259FlexibilityNo cancel feeOn-time65%
FrontierCheapest$136Average$278FlexibilityNo cancel feeOn-time62%
Sun Country AirCheapest$152Average$197FlexibilityNo cancel feeOn-time83%
DeltaCheapest$159Average$446FlexibilityNo cancel feeOn-timeN/A
United AirlinesCheapest$179Average$399FlexibilityNo cancel feeOn-time69%
Alaska AirlinesCheapest$199Average$412FlexibilityNo cancel feeOn-time75%
SouthwestCheapest$205Average$502FlexibilityNo cancel feeOn-time63%
American AirlinesCheapest$248Average$493FlexibilityNo cancel feeOn-time71%
JetBlueCheapest$258Average$323FlexibilityNo cancel feeOn-time62%

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