HomeSearch by dateVacation packagesHotelsFlight dealsCar rentalTravel tips & news
Porto

$218+ 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 10/7. Fares are subject to change and may not be available on all flights or dates of travel.
MIA — OPO
Oct 11 — Oct 181
Sat 10/11
Sat 10/18
1 adult, Economy
We work with more than 300 partners to bring you better travel deals

Find cheap flights from Key Largo to Porto with Cheapflights

1. Tell us where you want to go

Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”

2. Select your favorite providers

We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.

3. Compare prices and book

Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.

Cheapflights Tip: The best prices from Key Largo to Porto are usually found in February or January, booked 73 days in advance, depart on a Tuesday or Wednesday and return on a Thursday

Cheap 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 September 11, 2025.

Round-trip from

$400
(Mytrip)

One-way from

$218
(Connections by easyJet)

Popular in

December

Cheapest in

February

Average price

$721
From Key Largo to Porto
Search Deals
One-way flight from Key Largo to Porto
Search Deals
High demand for flights, 2% potential price rise
Search Deals
Cheapest flight prices on average. 3% potential price decrease ($23 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in September 2025
Search Deals

Find 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 September 11, 2025.

This Mytrip deal was found by Cheapflights users on 9/11. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/2710:45 pmMIA - OPO
1 stop28h 05mAir Europa
Wed 11/127:35 amOPO - MIA
1 stop16h 55mAir Europa
Deal found 9/11$400
This Cheapflightsfares deal was found by Cheapflights users on 9/11. 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 Cheapflightsfares is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/59:45 pmMIA - OPO
1 stop16h 35mAir Europa
Tue 11/1111:35 amOPO - MIA
1 stop12h 55mAir Europa
Deal found 9/11$422
This Mytrip deal was found by Cheapflights users on 9/10. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/198:00 amMIA - OPO
2 stops22h 15mMultiple Airlines
Mon 12/112:05 pmOPO - MIA
1 stop34h 25mMultiple Airlines
Deal found 9/10$432
This United Airlines deal was found by Cheapflights users on 9/10. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/2011:13 amMIA - OPO
1 stop17h 32mUnited Airlines
Wed 11/512:35 pmOPO - MIA
1 stop16h 24mUnited Airlines
Deal found 9/10$436
This United Airlines deal was found by Cheapflights users on 9/11. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/124:42 pmMIA - OPO
1 stop11h 48mUnited Airlines
Wed 11/1912:35 pmOPO - MIA
1 stop15h 29mUnited Airlines
Deal found 9/11$444
This Expedia deal was found by Cheapflights users on 9/9. 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 Expedia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/204:55 pmMIA - OPO
1 stop13h 45mMultiple Airlines
Wed 11/58:40 pmOPO - MIA
1 stop22h 05mMultiple Airlines
Deal found 9/9$446
This United Airlines deal was found by Cheapflights users on 9/10. 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 United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/277:00 amMIA - OPO
2 stops22h 30mUnited Airlines
Wed 11/1212:35 pmOPO - MIA
1 stop15h 29mUnited Airlines
Deal found 9/10$448
This Iberia deal was found by Cheapflights users on 9/11. 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 Iberia is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Mon 10/271:40 pmMIA - OPO
2 stops14h 00mIberia
Wed 11/128:20 amOPO - MIA
1 stop17h 25mIberia
Deal found 9/11$449

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 September 11, 2025.
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

Wed 2/4

9:45 pm-3:15 pm

1 stop12h 30m

Porto

Mon 2/23

8:10 pm-7:30 pm

1 stop28h 20m

$455

MiamiPorto

MIA - OPO

MIAOPO

Miami

Tue 2/3

9:45 pm-3:15 pm

1 stop12h 30m

Porto

Mon 2/23

8:10 pm-7:30 pm

1 stop28h 20m

$455

MiamiPorto

MIA - OPO

MIAOPO

Miami

Mon 10/20

3:33 pm-3:30 pm

2 stops18h 57m

Porto

Wed 11/5

11:25 am-8:20 pm

1 stop13h 55m

$464

MiamiPorto

MIA - OPO

MIAOPO

Miami

Wed 2/4

2:32 pm-1:15 pm

2 stops17h 43m

Porto

Thu 2/26

2:05 pm-4:55 pm

1 stop31h 50m

$467

MiamiPorto

MIA - OPO

MIAOPO

Miami

Tue 11/18

12:36 pm-10:30 am

2 stops16h 54m

Porto

Tue 12/2

11:10 am-8:20 pm

1 stop14h 10m

$468

MiamiPorto

MIA - OPO

MIAOPO

Miami

Mon 11/24

4:42 pm-9:30 am

1 stop11h 48m

Porto

Tue 12/2

12:30 pm-2:40 pm

1 stop31h 10m

$469

MiamiPorto

MIA - OPO

MIAOPO

Miami

Tue 11/25

4:50 pm-10:25 pm

1 stop24h 35m

Porto

Thu 12/11

11:15 am-2:50 pm

1 stop32h 35m

$480

MiamiPorto

MIA - OPO

MIAOPO

Miami

Thu 2/5

9:45 pm-3:15 pm

1 stop12h 30m

Porto

Fri 2/27

7:35 am-7:30 pm

1 stop16h 55m

$485

MiamiPorto

MIA - OPO

MIAOPO

Miami

Fri 11/28

4:40 pm-11:10 am

1 stop13h 30m

Porto

Tue 12/2

12:05 pm-2:40 pm

1 stop31h 35m

$486

MiamiPorto

MIA - OPO

MIAOPO

Miami

Mon 10/27

5:35 pm-5:00 pm

2 stops19h 25m

$226

Flights are sorted by cheapest round-trip flights first.

Deals found on 9/10

Showing 1-10 of 17 results
1
2

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 August 29, 2025.

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 73 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 $523). Flying from Key Largo to Porto in June is currently the most expensive (average of $1,027). 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 KE9 to OPO?

Find hourly flight availability from Key Largo to Porto. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated September 11, 2025.

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

What is the cheapest day to fly from Key Largo to Porto?

Use this chart to determine the cheapest time to fly round-trip from Key Largo to Porto. Price data was last updated on December 16, 2024.

Travelers seeking maximum savings on their Key Largo to Porto flight should consider departing on Tuesday afternoons when fares are most often at their lowest. Sunday afternoons flights should be avoided if possible as fares are typically the most expensive at this time.

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 September 11, 2025.
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
8,937 reviews

Entertainment

7.1

Food

6.6

Overall

7.4

Comfort

7.3

Boarding

7.7

Crew

8.1

Reviews

1 / 20
4.0
Okay

Thomas,Mar 2025

SFO - TPE

When I asked for an extra snack, I got an unhappy look from the stewardess. Geez, does one extra snack really affect the bottom line??
United Airlines
7.4
Good
8,937 reviews
United Airlines
7.4
Good
8,937 reviews

Entertainment

7.1

Food

6.6

Overall

7.4

Comfort

7.3

Boarding

7.7

Crew

8.1

Reviews

1 / 20
4.0
Okay

Thomas,Mar 2025

SFO - TPE

When I asked for an extra snack, I got an unhappy look from the stewardess. Geez, does one extra snack really affect the bottom line??
Air Canada
7.1
Good
10,000 reviews
United Airlines
7.4
Good
8,937 reviews

Entertainment

7.1

Food

6.6

Overall

7.4

Comfort

7.3

Boarding

7.7

Crew

8.1

Reviews

1 / 20
4.0
Okay

Thomas,Mar 2025

SFO - TPE

When I asked for an extra snack, I got an unhappy look from the stewardess. Geez, does one extra snack really affect the bottom line??
TAP AIR PORTUGAL
7.1
Good
1,977 reviews
United Airlines
7.4
Good
8,937 reviews

Entertainment

7.1

Food

6.6

Overall

7.4

Comfort

7.3

Boarding

7.7

Crew

8.1

Reviews

1 / 20
4.0
Okay

Thomas,Mar 2025

SFO - TPE

When I asked for an extra snack, I got an unhappy look from the stewardess. Geez, does one extra snack really affect the bottom line??
Air Europa
7.0
Good
556 reviews
United Airlines
7.4
Good
8,937 reviews

Entertainment

7.1

Food

6.6

Overall

7.4

Comfort

7.3

Boarding

7.7

Crew

8.1

Reviews

1 / 20
4.0
Okay

Thomas,Mar 2025

SFO - TPE

When I asked for an extra snack, I got an unhappy look from the stewardess. Geez, does one extra snack really affect the bottom line??
Iberia
7.0
Good
2,929 reviews
United Airlines
7.4
Good
8,937 reviews

Entertainment

7.1

Food

6.6

Overall

7.4

Comfort

7.3

Boarding

7.7

Crew

8.1

Reviews

1 / 20
4.0
Okay

Thomas,Mar 2025

SFO - TPE

When I asked for an extra snack, I got an unhappy look from the stewardess. Geez, does one extra snack really affect the bottom line??

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 $455, Air Europa can have you in Porto from Key Largo in 12h 30m. There are 4140 mi between Key Largo and Porto. Both multi-stop and nonstop flights can be found to your destination and back.

  • 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 $523). Flying from Key Largo to Porto in June is currently the most expensive (average of $1,027). 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
Aveiro
Arcos de Valdevez
Coimbra

Browse thousands of different options on Cheapflights for your next trip

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.

Alternative routes for Key Largo to Porto

See prices for flight routes from nearby airports that may be better suited for you.
Miami to Lisbon flights
Orlando to Lisbon flights
Fort Lauderdale to Lisbon flights
Tampa to Lisbon flights
Jacksonville to Lisbon flights
Miami to Porto flights
Orlando to Porto flights
West Palm Beach to Lisbon flights
Miami to Funchal flights
Jacksonville to Porto flights
Miami to Ponta Delgada flights
Fort Myers to Lisbon flights
Miami to Faro flights
Pensacola to Lisbon flights
Fort Lauderdale to Porto flights
Tampa to Porto flights
Orlando to Faro flights
Orlando to Funchal flights
Sarasota to Lisbon flights
West Palm Beach to Porto flights
Orlando to Ponta Delgada flights
Melbourne to Lisbon flights
Tampa to Ponta Delgada flights
West Palm Beach to Ponta Delgada flights
Daytona Beach to Lisbon flights
Tampa to Funchal flights
Tallahassee to Lisbon flights
Fort Lauderdale to Ponta Delgada flights
Valparaiso to Lisbon flights
Fort Myers to Ponta Delgada flights
Gainesville to Lisbon flights
West Palm Beach to Faro flights
Daytona Beach to Porto flights
Melbourne to Porto flights
Orlando to Lajes flights
Jacksonville to Ponta Delgada flights
Fort Lauderdale to Faro flights
Fort Lauderdale to Funchal flights
Tampa to Faro flights
Sarasota to Porto flights
Sarasota to Ponta Delgada flights
Miami to Vila do Porto flights
West Palm Beach to Funchal flights
Miami to Horta flights
Melbourne to Ponta Delgada flights

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 September 11, 2025.
AirlineCheapestAverageFlexibilityOn-time
SWISSCheapest$377Average$523FlexibilityNo cancel feeOn-time79%
Air EuropaCheapest$469Average$726FlexibilityNo cancel feeOn-time83%
TAP AIR PORTUGALCheapest$470Average$749FlexibilityNo cancel feeOn-timeN/A
American AirlinesCheapest$503Average$741FlexibilityNo cancel feeOn-time71%
IberiaCheapest$525Average$689FlexibilityNo cancel feeOn-time77%
British AirwaysCheapest$527Average$693FlexibilityNo cancel feeOn-time70%
United AirlinesCheapest$532Average$726FlexibilityNo cancel feeOn-time69%
LufthansaCheapest$550Average$753FlexibilityNo cancel feeOn-time76%
Air CanadaCheapest$553Average$932FlexibilityNo cancel feeOn-time67%
DeltaCheapest$565Average$702FlexibilityNo cancel feeOn-timeN/A

100% Free

Cheapflights is completely free to use, so you can start saving the moment you arrive.

Book with Flexibility

Our users can plan ahead with confidence and find flights with no change fees

Travel Smart

Millions of people come to us for their flight needs every year. We help make travel planning easy by providing useful insights and data-driven graphs that can inform your decisions.