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$230+ Cheap flights from Key Largo, FL to Porto (OPO)

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 4/29. Fares are subject to change and may not be available on all flights or dates of travel.
MIA — OPO
Feb 28 — Mar 71
Sat 2/28
Sat 3/7
1 adult, Economy
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Cheap flight deals from Key Largo to Porto

Cheapest flights from Key Largo to Porto
Explore the most affordable flight options available from Key Largo to Porto. Find the lowest fares from popular airlines and budget airlines, with prices last updated on January 29, 2026.

This oojo deal was found by Cheapflights users on 1/27. 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 oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 3/95:35 pm
MIA
-
OPO
1 stop17h 25m
TAP AIR PORTUGAL
Thu 3/198:00 pm
OPO
-
MIA
1 stop23h 50m
TAP AIR PORTUGAL
Deal found 1/27$372
This Kiwi.com deal was found by Cheapflights users on 1/28. 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.
Wed 2/1111:35 pm
MIA
-
OPO
1 stop10h 30m
TAP AIR PORTUGAL
Sat 2/288:00 pm
OPO
-
MIA
1 stop23h 50m
TAP AIR PORTUGAL
Deal found 1/28$398
This Kiwi.com deal was found by Cheapflights users on 1/28. 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.
Wed 2/114:35 pm
MIA
-
OPO
1 stop12h 40m
TAP AIR PORTUGAL
Wed 2/252:00 pm
OPO
-
MIA
1 stop12h 50m
TAP AIR PORTUGAL
Deal found 1/28$399
This Ovago deal was found by Cheapflights users on 1/28. 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 Ovago is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 2/811:50 pm
MIA
-
OPO
1 stop13h 15m
TAP AIR PORTUGAL
Wed 2/256:55 am
OPO
-
MIA
1 stop12h 55m
TAP AIR PORTUGAL
Deal found 1/28$417
This Kiwi.com deal was found by Cheapflights users on 1/27. 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.
Wed 2/189:45 pm
MIA
-
OPO
1 stop32h 05m
Air Europa
Wed 2/2511:35 am
OPO
-
MIA
1 stop12h 55m
Air Europa
Deal found 1/27$418
This Kiwi.com deal was found by Cheapflights users on 1/26. 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 2/169:45 pm
MIA
-
OPO
1 stop12h 30m
Air Europa
Mon 2/234:05 pm
OPO
-
MIA
1 stop32h 25m
Air Europa
Deal found 1/26$421
This Kiwi.com deal was found by Cheapflights users on 1/26. 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.
Tue 2/179:45 pm
MIA
-
OPO
1 stop32h 05m
Air Europa
Tue 2/244:05 pm
OPO
-
MIA
1 stop32h 25m
Air Europa
Deal found 1/26$429
This oojo deal was found by Cheapflights users on 1/27. 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 oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 5/1712:30 am
MIA
-
OPO
1 stop11h 30m
TAP AIR PORTUGAL
Sun 5/317:05 am
OPO
-
MIA
1 stop12h 25m
TAP AIR PORTUGAL
Deal found 1/27$448
This oojo deal was found by Cheapflights users on 1/28. 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 oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Tue 2/34:35 pm
MIA
-
OPO
1 stop17h 25m
TAP AIR PORTUGAL
Wed 2/182:00 pm
OPO
-
MIA
1 stop12h 50m
TAP AIR PORTUGAL
Deal found 1/28$453
This oojo deal was found by Cheapflights users on 1/28. 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 oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 2/29:45 pm
MIA
-
OPO
1 stop16h 35m
Air Europa
Wed 2/187:35 am
OPO
-
MIA
1 stop16h 55m
Air Europa
Deal found 1/28$467
This oojo deal was found by Cheapflights users on 1/27. 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 oojo is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 1/2811:35 pm
MIA
-
OPO
1 stop13h 25m
TAP AIR PORTUGAL
Sun 2/19:55 am
OPO
-
MIA
1 stop17h 10m
TAP AIR PORTUGAL
Deal found 1/27$473

Find flight deals from Key Largo to Porto

Keep the following information in mind while searching for Key Largo to Porto flight deals. Data was last updated January 29, 2026.

Most accurate provider

FlightHub
3 stars

Most trusted provider

FlightHub
3 stars

Round-trip from

$372
(oojo)

One-way from

$230
(Flysmarter)

Popular in

December

Cheapest in

January

Average price

$470
Provider with most accurate pricing for Miami-Porto flight deals.
Search Deals
Provider most trusted by Cheapflights users for Miami-Porto flights.
Search Deals
From Key Largo to Porto
Search Deals
One-way flight from Key Largo to Porto
Search Deals
Highest demand for flights based on searches. 2% potential increase in price ($20 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 4% potential price decrease ($28 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in January 2026
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from Key Largo to Porto 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 January 29, 2026.
Use the filters below to find and compare flights from Key Largo to Porto that are best for you.

Fly from

Key Largo

Fly to

Porto

Route

Depart

Return

Price

MiamiPorto

MIA - OPO

MIAOPO

Miami

Mon 2/16

4:35 pm-10:00 am

1 stop12h 25m

Porto

Wed 2/25

6:55 am-2:50 pm

1 stop12h 55m

$478

MiamiPorto

MIA - OPO

MIAOPO

Miami

Tue 3/24

5:40 pm-11:15 am

1 stop13h 35m

Porto

Tue 5/5

12:15 pm-5:25 pm

1 stop34h 10m

$493

MiamiPorto

MIA - OPO

MIAOPO

Miami

Tue 3/24

5:40 pm-11:15 am

1 stop13h 35m

Porto

Tue 4/28

12:15 pm-5:25 pm

1 stop34h 10m

$494

MiamiPorto

MIA - OPO

MIAOPO

Miami

Mon 2/16

9:45 pm-7:20 pm

1 stop16h 35m

Porto

Thu 2/26

7:35 am-7:30 pm

1 stop16h 55m

$496

MiamiPorto

MIA - OPO

MIAOPO

Miami

Tue 2/17

8:00 pm-10:30 am

1 stop33h 30m

Porto

Mon 2/23

11:15 am-2:50 pm

1 stop32h 35m

$496

MiamiPorto

MIA - OPO

MIAOPO

Miami

Tue 2/17

9:45 pm-3:15 pm

1 stop12h 30m

Porto

Fri 2/27

7:35 am-7:30 pm

1 stop16h 55m

$496

MiamiPorto

MIA - OPO

MIAOPO

Miami

Mon 2/9

9:45 pm-3:15 pm

1 stop12h 30m

Porto

Tue 2/24

7:35 am-7:30 pm

1 stop16h 55m

$497

MiamiPorto

MIA - OPO

MIAOPO

Miami

Mon 2/9

9:45 pm-3:15 pm

1 stop12h 30m

Porto

Thu 2/26

11:35 am-7:30 pm

1 stop12h 55m

$497

MiamiPorto

MIA - OPO

MIAOPO

Miami

Sun 2/8

9:45 pm-3:15 pm

1 stop12h 30m

Porto

Thu 2/19

11:35 am-7:30 pm

1 stop12h 55m

$497

MiamiPorto

MIA - OPO

MIAOPO

Miami

Tue 2/10

1:21 pm-10:30 am

2 stops16h 09m

Porto

Thu 2/19

5:00 am-6:21 pm

2 stops18h 21m

$507

Flights are sorted by cheapest round-trip flights first.

Deals found on 1/27

Showing 1-10 of 21 results
1
2
3

Best time to book a flight from Key Largo to Porto

Have a flexible travel schedule? Discover the best time to fly to Porto from Key Largo 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 Key Largo to Porto

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

Use this chart to determine the optimal time to book a round-trip flight from Key Largo to Porto. Price data was last updated on January 23, 2026.

The price you pay for your flight from Key Largo to Porto may vary depending on when you book. For the best chance of a lower fare, look to book 25 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 Key Largo to Porto?

Currently, January is the cheapest month in which you can book a flight from Key Largo to Porto (average of $438). Flying from Key Largo to Porto in June is currently the most expensive (average of $637). 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.

Reviews of airlines servicing Porto

Get insights into the airlines that provide service to Porto. 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 Porto. Reviews last updated January 29, 2026.
See what other customers who have flown with United Airlines, Air Canada, and TAP AIR PORTUGAL from Key Largo to Porto have to say. You can also see how each airline compares in terms of entertainment options, comfort, food, crew/service, and boarding process.
United Airlines
7.4
Good
9,215 reviews

Food

6.6

Boarding

7.7

Comfort

7.3

Overall

7.4

Crew

8.1

Entertainment

7.1

Reviews

1 / 20
10.0
Excellent

Dane,Jan 2026

TYS - IAD

It was a short flight, so no time for amenities. Just glad everything was quick and easy from boarding to arriving at my destination with my family
United Airlines
7.4
Good
9,215 reviews
United Airlines
7.4
Good
9,215 reviews

Food

6.6

Boarding

7.7

Comfort

7.3

Overall

7.4

Crew

8.1

Entertainment

7.1

Reviews

1 / 20
10.0
Excellent

Dane,Jan 2026

TYS - IAD

It was a short flight, so no time for amenities. Just glad everything was quick and easy from boarding to arriving at my destination with my family
Air Canada
7.1
Good
10,667 reviews
United Airlines
7.4
Good
9,215 reviews

Food

6.6

Boarding

7.7

Comfort

7.3

Overall

7.4

Crew

8.1

Entertainment

7.1

Reviews

1 / 20
10.0
Excellent

Dane,Jan 2026

TYS - IAD

It was a short flight, so no time for amenities. Just glad everything was quick and easy from boarding to arriving at my destination with my family
TAP AIR PORTUGAL
7.1
Good
2,130 reviews
United Airlines
7.4
Good
9,215 reviews

Food

6.6

Boarding

7.7

Comfort

7.3

Overall

7.4

Crew

8.1

Entertainment

7.1

Reviews

1 / 20
10.0
Excellent

Dane,Jan 2026

TYS - IAD

It was a short flight, so no time for amenities. Just glad everything was quick and easy from boarding to arriving at my destination with my family
Iberia
7.0
Good
3,100 reviews
United Airlines
7.4
Good
9,215 reviews

Food

6.6

Boarding

7.7

Comfort

7.3

Overall

7.4

Crew

8.1

Entertainment

7.1

Reviews

1 / 20
10.0
Excellent

Dane,Jan 2026

TYS - IAD

It was a short flight, so no time for amenities. Just glad everything was quick and easy from boarding to arriving at my destination with my family
Air Europa
6.9
Okay
587 reviews
United Airlines
7.4
Good
9,215 reviews

Food

6.6

Boarding

7.7

Comfort

7.3

Overall

7.4

Crew

8.1

Entertainment

7.1

Reviews

1 / 20
10.0
Excellent

Dane,Jan 2026

TYS - IAD

It was a short flight, so no time for amenities. Just glad everything was quick and easy from boarding to arriving at my destination with my family

Related info for your journey

Find useful and relevant information for your journey from Key Largo to Porto. 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 into for flights to Porto from Key Largo?

    If you book a flight to Porto from Key Largo, you will be flying to Porto, which is the city’s only airport. Porto (OPO) is located 6.8 mi from the center of Porto. There are 0 flights from Key Largo to Porto per day from 11 different airlines.

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

    For as low as $478, TAP AIR PORTUGAL can have you in Porto from Key Largo in 12h 25m. There are 4140 mi between Key Largo and Porto. Both multi-stop and nonstop flights can be found to your destination and back.

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

    The cheapest airline one-way is TAP AIR PORTUGAL, with whom users have recently found tickets for as low as $253. However, be on the lookout for offers from United Airlines and Iberia, as they are both options that can get you from Key Largo to Porto for a low price.

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

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

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

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

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

    Yes. Cheapflights offers flight deals from Key Largo to Porto 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 Key Largo to Porto?

    Currently, January is the cheapest month in which you can book a flight from Key Largo to Porto (average of $438). Flying from Key Largo to Porto in June is currently the most expensive (average of $637). 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

Traveling to a place near Porto?

Book flights to Porto if you plan to visit one of these locations
Vila Nova de Gaia
Aveiro
Arcos de Valdevez
Coimbra

Browse thousands of different options on Cheapflights for your next trip

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Top 10 airlines flying from Key Largo to Porto

Discover the top 10 airlines that operate flights from Key Largo to Porto. 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 January 29, 2026.
AirlineCheapestAverageFlexibilityOn-time
TAP AIR PORTUGALCheapest$453Average$749FlexibilityNo cancel feeOn-timeN/A
American AirlinesCheapest$479Average$743FlexibilityNo cancel feeOn-time71%
Air EuropaCheapest$482Average$728FlexibilityNo cancel feeOn-time83%
DeltaCheapest$492Average$703FlexibilityNo cancel feeOn-timeN/A
KLMCheapest$494Average$614FlexibilityNo cancel feeOn-time75%
SWISSCheapest$507Average$643FlexibilityNo cancel feeOn-time79%
IberiaCheapest$510Average$667FlexibilityNo cancel feeOn-time77%
British AirwaysCheapest$521Average$693FlexibilityNo cancel feeOn-time70%
United AirlinesCheapest$532Average$718FlexibilityNo cancel feeOn-time69%
Air CanadaCheapest$553Average$876FlexibilityNo cancel feeOn-time67%

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