HomeSearch by dateVacation packagesHotelsFlight dealsCar rentalTravel tips & news
Portsmouth

$504+ Cheap flights from Key Largo, FL to Portsmouth, England

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 3/10. Fares are subject to change and may not be available on all flights or dates of travel.
MIA — LHR
Nov 29 — Dec 61
Sat 11/29
Sat 12/6
1 adult, Economy
We work with more than 300 partners to bring you better travel deals

Find cheap flights from Key Largo to Portsmouth 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.

Find flight deals from Key Largo to Portsmouth

Cheapest flights from Key Largo to Portsmouth
Explore the most affordable flight options available from Key Largo to Portsmouth. Find the lowest fares from popular airlines and budget airlines, with prices last updated on October 30, 2025.

This Air France deal was found by Cheapflights users on 10/30. 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 Air France is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Thu 11/134:50 pmMIA - SOU
1 stop19h 10mKLM
Sun 11/169:30 amSOU - MIA
2 stops18h 43mKLM
Deal found 10/30$1,000
This Delta deal was found by Cheapflights users on 10/29. 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.
Tue 11/44:50 pmMIA - SOU
1 stop19h 10mDelta
Sun 11/96:05 pmSOU - MIA
2 stops35h 41mDelta
Deal found 10/29$1,075
This KAYAK deal was found by Cheapflights users on 10/29. 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 KAYAK is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 11/56:55 pmMIA - SOU
1 stop15h 40mAer Lingus
Sun 11/99:30 amSOU - MIA
1 stop12h 40mAer Lingus
Deal found 10/29$1,188
This Delta deal was found by Cheapflights users on 10/29. 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.
Tue 12/236:00 amMIA - SOU
2 stops30h 00mDelta
Thu 1/18:50 amSOU - MIA
2 stops19h 16mDelta
Deal found 10/29$1,229
This Trip.com deal was found by Cheapflights users on 10/28. 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 Trip.com is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/124:50 pmMIA - SOU
1 stop11h 00mVirgin Atlantic
Fri 12/195:30 pmSOU - MIA
2 stops35h 01mVirgin Atlantic
Deal found 10/28$1,256
This Priceline deal was found by Cheapflights users on 10/28. 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 Priceline is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/127:05 pmMIA - SOU
1 stop32h 40mAer Lingus
Fri 12/199:30 amSOU - MIA
2 stops18h 34mAer Lingus
Deal found 10/28$1,258
This Mytrip deal was found by Cheapflights users on 10/28. 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 Mytrip is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Fri 12/1210:19 amMIA - SOU
3 stops23h 31mMultiple Airlines
Fri 12/199:30 amSOU - MIA
3 stops28h 45mMultiple Airlines
Deal found 10/28$1,278
This Delta deal was found by Cheapflights users on 10/29. 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.
Thu 12/254:50 pmMIA - SOU
1 stop19h 10mDelta
Thu 1/18:50 amSOU - MIA
2 stops19h 16mDelta
Deal found 10/29$1,284
This Mytrip deal was found by Cheapflights users on 10/30. 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.
Thu 11/131:02 pmMIA - SOU
3 stops25h 18mMultiple Airlines
Sun 11/169:30 amSOU - MIA
2 stops34h 10mMultiple Airlines
Deal found 10/30$1,286

Cheap flight deals from Key Largo to Portsmouth

Keep the following information in mind while searching for Key Largo to Portsmouth flight deals. Data was last updated October 30, 2025.

Most accurate provider

CheapOair
3 stars

Most trusted provider

CheapOair
3 stars

Round-trip from

$869
(Delta)

One-way from

$504
(Delta)

Popular in

March

Cheapest in

September

Average price

$1,545
Provider with most accurate pricing for Miami-London (LON) flight deals.
Search Deals
Provider most trusted by Cheapflights users for Miami-London (LON) flights.
Search Deals
From Key Largo to Portsmouth
Search Deals
One-way flight from Key Largo to Portsmouth
Search Deals
Highest demand for flights based on searches. 5% potential increase in price ($59 potential increase over avg. RT price).
Search Deals
Cheapest flight prices on average. 6% potential price decrease ($71 potential savings vs. average RT price).
Search Deals
Average for round-trip flights in October 2025
Search Deals

Cheapflights Fare Finder

 
Customize your flight search to find flights from Key Largo to Portsmouth 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 October 30, 2025.
Use the filters below to find and compare flights from Key Largo to Portsmouth that are best for you.

Fly from

Key Largo

Fly to

Portsmouth

Route

Depart

Return

Price

MiamiSouthampton

MIA - SOU

MIASOU

Miami

Mon 4/6

7:30 am-5:00 pm

2 stops28h 30m

Southampton Eastleigh

Mon 4/27

5:35 pm-5:09 pm

2 stops28h 34m

$869

MiamiSouthampton

MIA - SOU

MIASOU

Miami

Mon 4/6

1:45 pm-5:00 pm

2 stops22h 15m

Southampton Eastleigh

Tue 4/28

5:35 pm-5:09 pm

2 stops28h 34m

$869

MiamiSouthampton

MIA - SOU

MIASOU

Miami

Mon 4/6

7:30 am-5:00 pm

2 stops28h 30m

Southampton Eastleigh

Thu 4/30

5:35 pm-5:09 pm

2 stops28h 34m

$869

MiamiSouthampton

MIA - SOU

MIASOU

Miami

Wed 4/8

12:01 pm-5:00 pm

2 stops23h 59m

Southampton Eastleigh

Fri 5/1

5:35 pm-10:13 am

2 stops21h 38m

$869

MiamiSouthampton

MIA - SOU

MIASOU

Miami

Wed 4/8

6:30 pm-5:00 pm

2 stops17h 30m

Southampton Eastleigh

Tue 4/28

9:20 am-10:53 pm

2 stops18h 33m

$869

MiamiSouthampton

MIA - SOU

MIASOU

Miami

Tue 4/7

8:45 am-5:00 pm

2 stops27h 15m

Southampton Eastleigh

Fri 5/1

5:35 pm-10:13 am

2 stops21h 38m

$869

MiamiSouthampton

MIA - SOU

MIASOU

Miami

Mon 4/6

7:30 pm-5:00 pm

2 stops16h 30m

Southampton Eastleigh

Fri 5/1

5:35 pm-10:13 am

2 stops21h 38m

$869

MiamiSouthampton

MIA - SOU

MIASOU

Miami

Tue 4/7

8:45 am-5:00 pm

2 stops27h 15m

Southampton Eastleigh

Wed 4/29

5:35 pm-10:13 am

2 stops21h 38m

$869

MiamiSouthampton

MIA - SOU

MIASOU

Miami

Sat 4/11

7:55 pm-8:50 am

2 stops31h 55m

Southampton Eastleigh

Wed 4/29

5:35 pm-10:45 am

2 stops22h 10m

$876

MiamiSouthampton

MIA - SOU

MIASOU

Miami

Sat 4/11

7:55 pm-8:50 am

2 stops31h 55m

Southampton Eastleigh

Mon 4/27

5:35 pm-5:09 pm

2 stops28h 34m

$876

Flights are sorted by cheapest round-trip flights first.

Deals found on 10/27

Showing 1-10 of 21 results
1
2
3

Best time to book a flight from Key Largo to Portsmouth

Have a flexible travel schedule? Discover the best time to fly to Portsmouth 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 Portsmouth

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

Currently, January is the cheapest month in which you can book a flight from Key Largo to Portsmouth (average of $286). Flying from Key Largo to Portsmouth in June is currently the most expensive (average of $493). 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 P0R?

Find hourly flight availability from Key Largo to Portsmouth. Discover flight options and departure times throughout the day, allowing you to choose a departure time that suits your schedule. Data last updated October 30, 2025.

When flying from Key Largo to Portsmouth, the time of day you fly usually plays a role in the price. Save by searching for a flight at noon, which can drop the price by up to 14% versus a flight in the morning.

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

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

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

Reviews of airlines servicing Portsmouth

Get insights into the airlines that provide service to Portsmouth. 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 Portsmouth. Reviews last updated October 30, 2025.
Peruse reviews from past customers who have flown with Delta from Key Largo to Portsmouth to help guide your decision. You can also see how each airline stacks up in terms of entertainment options, comfort, food, crew/service, and boarding process.
Delta
7.9
Good
7,998 reviews

Crew

8.5

Boarding

8.2

Comfort

7.9

Entertainment

7.9

Food

7.3

Overall

7.9

Reviews

1 / 20
6.0
Good

pilar,May 2025

RSW - ATL

The stewardess was not very nice because I requested two glasses of water. She didn’t even offer the snacks to me. She seemed angry and I felt very bad about her reaction. Also, the flight was full and you could not move. The airline should provide seats for obese people in consideration to the rest pf the passengers.
Delta
7.9
Good
7,998 reviews
Delta
7.9
Good
7,998 reviews

Crew

8.5

Boarding

8.2

Comfort

7.9

Entertainment

7.9

Food

7.3

Overall

7.9

Reviews

1 / 20
6.0
Good

pilar,May 2025

RSW - ATL

The stewardess was not very nice because I requested two glasses of water. She didn’t even offer the snacks to me. She seemed angry and I felt very bad about her reaction. Also, the flight was full and you could not move. The airline should provide seats for obese people in consideration to the rest pf the passengers.

Related info for your journey

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

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

    Airlines like Delta fly from Key Largo to Portsmouth in about 28h 30m. The time it takes to get you to your destination can typically vary by up to . Key Largo and Portsmouth are separated by a distance of 4381 mi.

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

    No one likes to see their flight delayed. When booking a flight from Key Largo to Portsmouth consider choosing KLM (92%), Air France (92%) or Delta (92%) as they are the most reliable in getting you off to your destination on time.

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

    While on average a flight from Key Largo to Portsmouth is generally $2,656, our data shows the cheapest flight currently is $421. When looking at the most popular route, (Miami - Southampton Eastleigh), you can expect to pay $636 for that flight.

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

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

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

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

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

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

    Currently, January is the cheapest month in which you can book a flight from Key Largo to Portsmouth (average of $286). Flying from Key Largo to Portsmouth in June is currently the most expensive (average of $493). 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

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

Alternative routes for Key Largo to Portsmouth

See prices for flight routes from nearby airports that may be better suited for you.
Miami to Heathrow flights
Orlando to Heathrow flights
Tampa to Heathrow flights
Orlando to Gatwick flights
Miami to Gatwick flights
Miami to London City flights
Orlando to London City flights
Fort Lauderdale to Heathrow flights
Miami to Stansted flights
Miami to Luton flights
Orlando to Stansted flights
Tampa to Gatwick flights
Tampa to London City flights
Fort Lauderdale to Gatwick flights
Orlando to Luton flights
Orlando to Manchester flights
Orlando to Edinburgh flights
West Palm Beach to Heathrow flights
Tampa to Stansted flights
Jacksonville to Heathrow flights
Fort Myers to Heathrow flights
Pensacola to Heathrow flights
West Palm Beach to Gatwick flights
Jacksonville to Gatwick flights
Tampa to Luton flights
Miami to Edinburgh flights
Fort Lauderdale to London City flights
Fort Myers to Gatwick flights
Miami to Manchester flights
Panama City to Heathrow flights
Sarasota to Heathrow flights
Valparaiso to Heathrow flights
Fort Myers to London City flights
Tampa to Manchester flights
Jacksonville to Edinburgh flights
Pensacola to London City flights
Fort Lauderdale to Luton flights
Daytona Beach to Heathrow flights
Fort Lauderdale to Stansted flights
Jacksonville to Manchester flights
West Palm Beach to London City flights
West Palm Beach to Manchester flights
Tampa to Edinburgh flights
Fort Lauderdale to Edinburgh flights
Fort Lauderdale to Manchester flights
Jacksonville to London City flights
Pensacola to Gatwick flights
Melbourne to Heathrow flights
Fort Myers to Stansted flights
Tallahassee to Heathrow flights

Top 10 airlines flying from Key Largo to Portsmouth

Discover the top 10 airlines that operate flights from Key Largo to Portsmouth. 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 October 30, 2025.
AirlineCheapestAverageFlexibilityOn-time
JetBlueCheapest$51Average$750FlexibilityNo cancel feeOn-time62%
Scandinavian AirlinesCheapest$203Average$578FlexibilityNo cancel feeOn-time77%
Norse Atlantic UKCheapest$350Average$564FlexibilityNo cancel feeOn-timeN/A
British AirwaysCheapest$358Average$740FlexibilityNo cancel feeOn-time70%
Air CanadaCheapest$432Average$611FlexibilityNo cancel feeOn-time67%
DeltaCheapest$461Average$939FlexibilityNo cancel feeOn-timeN/A
Virgin AtlanticCheapest$479Average$759FlexibilityNo cancel feeOn-time72%
FinnairCheapest$512Average$877FlexibilityNo cancel feeOn-time76%
American AirlinesCheapest$519Average$803FlexibilityNo cancel feeOn-time71%
TAP AIR PORTUGALCheapest$532Average$740FlexibilityNo 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.