Last year, Southwest Airlines announced it would partner with Icelandair to connect passengers from across its network to Iceland and beyond. The airline previously revealed it would launch the partnership with connections at Baltimore/Washington International and has now revealed that Denver and Nashville will also serve as network connection points.

Thrice as nice

The two airlines signed a Memorandum of Understanding on a strategic partnership last year. This partnership will allow customers to easily connect between the two airlines’ networks, with sales and travel through Baltimore/Washington International Thurgood Marshall Airport (BWI) launching next month. Speaking to Simple Flying last year, Icelandair officials confirmed that the partnership is vital to expanding the carrier's reach across the United States.

While Icelandair has existing partnerships with JetBlue and Alaska Airlines, the Southwest Airlines partnership represents an opportunity to bring passengers from across the US to Iceland, thanks to Southwest's significant domestic presence, with Icelandair's Director for North America, Grimur Gislason.

Southwest Airlines is the largest domestic carrier in the US in terms of passenger volume, edging out American Airlines for the top spot.

Thrice as nice

As of yesterday, January 15th, the two airlines confirmed they are expanding the partnership to two new airports: Nashville, Tennessee, and Denver, Colorado. Simple Flying first predicted those would be the next two cities last month at the sidelines of Icelandair’s Airbus A321LR delivery.

The additions will open new and exciting possibilities for customers of both airlines this summer, who will then be able to travel via Baltimore, Nashville, and Denver onwards to Iceland and Europe. Meanwhile, Europeans will be able to travel from Iceland to Southwest’s extensive network via the three gateways. 

Icelandair's seasonal flights from Nashville International Airport (BNA) to Reykjavík's Keflavik International Airport (KEF) start on April 10th, 2025. The flights will be operated by a Boeing 737-800 MAX aircraft, which seats 16 passengers in Saga Premium and 144 in economy. The flight will last around 7 hours and operate four days a week: Monday, Wednesday, Friday, and Sunday.

The route was so successful before it even launched that the airline brought forward the debut to meet passenger demand. From Nashville, passengers can connect to around 60 destinations.

Beginning in March, Southwest will start flying from Music City to Indianapolis International Airport (IND), Mexico's Los Cabos International Airport (SJD), and Punta Cana Airport (PUJ) in the Dominican Republic.

The agreement will also cover connections through Denver International Airport (DEN), another focus city for Southwest Airlines. Icelandair began service at DEN in May 2012 and has consistently carried nearly 10% of Denver-Europe passengers in the years since.

Passengers can connect onto any of the 85 routes Southwest currently operates from Denver. 

Passengers will also be able to connect through Baltimore/Washington International Thurgood Marshall Airport, as previously announced. Starting June 5th, Southwest will add nonstop transcontinental flights between BWI Marshall and six west coast markets: Long Beach (LGB), Ontario (ONT), Portland (PDX), San Francisco (SFO), San Jose (SJC), and Seattle (SEA).