Most Active Airlines in United States

Key Takeaways

  • 370 airlines fly scheduled routes from the United States. Together they operate 17,607 distinct outgoing routes from the country's airports
  • Southwest runs the widest network. 1,698 outgoing routes from the United States — about 1.2x the next airline
  • ORD is the busiest hub. Ranked by the number of outgoing routes departing each airport
  • Every airline mapped. Each of the top 12 carriers gets a map of where it flies from the United States

Which airlines are most active in the United States? Using live AirportRoutes data, we ranked every airline by the number of distinct outgoing routes it operates from the United States’s airports — each origin-to-destination pair counted once. Below, every one of the top 12 carriers gets a map of where it flies.

Bar chart of the most active airlines in United States by outgoing routes
The 10 most active airlines in United States, ranked by distinct outgoing routes. Data: AirportRoutes.

The Full Ranking

Full ranking

Most Active Airlines in United States

By distinct outgoing routes operated from the country’s airports.

Airline Routes Destinations Busiest base
1. Southwest1,698125Main hub: DEN
2. SkyWest1,471264Main hub: DEN
3. Delta Air Lines1,197233Main hub: ATL
4. American Airlines1,169231Main hub: DFW
5. United1,057224Main hub: DEN
6. Allegiant Air884131Main hub: SFB
7. Republic731104Main hub: ORD
8. Envoy Air662188Main hub: ORD
9. Frontier66189Main hub: DEN
10. Breeze Airways49475Main hub: RDU
11. PSA Airlines460103Main hub: DCA
12. Spirit44482Main hub: FLL

"Routes" = distinct origin-destination city pairs departing the country, counted once. Regularly-served routes only. Data: AirportRoutes.

Where the Routes Are: United States’s Busiest Airports

Map of the busiest airports in United States by number of outgoing routes
United States's busiest airports by number of outgoing routes. Data: AirportRoutes · Map: Mappr.

Each Airline — Where It Flies

Pick an airline and toggle Domestic / Continental / Intercontinental to see where each one flies. Click a dot for details.

1. Southwest

1,698 outgoing routes from 111 airports in the United States to 125 destinations (108 domestic, 17 international). Busiest bases: DEN, MDW, BWI. Top destinations include Denver, Baltimore, Las Vegas, Dallas, Chicago.

2. SkyWest

1,471 outgoing routes from 266 airports in the United States to 264 destinations (243 domestic, 21 international). Busiest bases: DEN, ORD, MSP. Top destinations include Denver, Chicago, Salt Lake City, Dallas-Fort Worth, Los Angeles.

3. Delta Air Lines

1,197 outgoing routes from 154 airports in the United States to 233 destinations (148 domestic, 85 international). Busiest bases: ATL, MSP, JFK. Top destinations include Atlanta, Detroit, Minneapolis, Salt Lake City, Los Angeles.

4. American Airlines

1,169 outgoing routes from 129 airports in the United States to 231 destinations (129 domestic, 102 international). Busiest bases: DFW, MIA, CLT. Top destinations include Dallas-Fort Worth, Charlotte, Miami, Phoenix, Chicago.

5. United

1,057 outgoing routes from 131 airports in the United States to 224 destinations (122 domestic, 102 international). Busiest bases: DEN, IAH, EWR. Top destinations include Denver, Chicago, Houston, Newark, San Francisco.

6. Allegiant Air

884 outgoing routes from 124 airports in the United States to 131 destinations (128 domestic, 3 international). Busiest bases: SFB, PIE, PGD. Top destinations include Orlando, St Petersburg-Clearwater, Las Vegas, Phoenix, Punta Gorda.

7. Republic

731 outgoing routes from 109 airports in the United States to 104 destinations (99 domestic, 5 international). Busiest bases: ORD, LGA, DCA. Top destinations include New York, Chicago, Newark, Washington, Boston.

8. Envoy Air

662 outgoing routes from 173 airports in the United States to 188 destinations (164 domestic, 24 international). Busiest bases: ORD, DFW, MIA. Top destinations include Dallas-Fort Worth, Chicago, Miami, Phoenix, Charlotte.

9. Frontier

661 outgoing routes from 87 airports in the United States to 89 destinations (75 domestic, 14 international). Busiest bases: DEN, ATL, MCO. Top destinations include Atlanta, Denver, Orlando, Dallas-Fort Worth, Las Vegas.

10. Breeze Airways

494 outgoing routes from 75 airports in the United States to 75 destinations (74 domestic, 1 international). Busiest bases: RDU, CHS, TPA. Top destinations include Orlando, Tampa, Raleigh/Durham, Fort Myers, Charleston.

11. PSA Airlines

460 outgoing routes from 109 airports in the United States to 103 destinations (97 domestic, 6 international). Busiest bases: DCA, CLT, PHL. Top destinations include Charlotte, Washington, Dallas-Fort Worth, Philadelphia, Chicago.

12. Spirit

444 outgoing routes from 56 airports in the United States to 82 destinations (58 domestic, 24 international). Busiest bases: FLL, MCO, LAS. Top destinations include Fort Lauderdale, Orlando, Las Vegas, Newark, Detroit.

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