Most Active Airlines in United States

Key Takeaways

370 airlines fly scheduled routes from the United States. Together they operate 17,723 distinct outgoing routes from the country's airports
Southwest runs the widest network. 1,705 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. Explore each carrier's network on the interactive map below

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.

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. Southwest	1,705	126	Main hub: DEN
2. SkyWest	1,472	264	Main hub: DEN
3. Delta Air Lines	1,203	234	Main hub: ATL
4. American Airlines	1,174	234	Main hub: DFW
5. United	1,059	225	Main hub: DEN
6. Allegiant Air	887	131	Main hub: SFB
7. Republic	731	104	Main hub: ORD
8. Frontier	663	89	Main hub: DEN
9. Envoy Air	662	188	Main hub: ORD
10. Breeze Airways	497	75	Main hub: RDU
11. PSA Airlines	461	103	Main hub: DCA
12. Spirit	444	82	Main hub: FLL

Where the Routes Are: United States’s Busiest Airports

Map of the busiest airports in United States — 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

1,705 outgoing routes from 111 airports in the United States to 126 destinations (108 domestic, 18 international). Busiest bases: DEN, MDW, BWI. Top destinations include Denver, Baltimore, Las Vegas, Dallas, Chicago.

2. SkyWest

1,472 outgoing routes from 266 airports in the United States to 264 destinations (243 domestic, 21 international). Busiest bases: DEN, ORD, MSP. Top destinations include Chicago, Denver, Salt Lake City, Dallas-Fort Worth, Los Angeles.

3. Delta Air Lines

1,203 outgoing routes from 154 airports in the United States to 234 destinations (148 domestic, 86 international). Busiest bases: ATL, MSP, JFK. Top destinations include Atlanta, Detroit, Minneapolis, Salt Lake City, Los Angeles.

4. American Airlines

1,174 outgoing routes from 129 airports in the United States to 234 destinations (132 domestic, 102 international). Busiest bases: DFW, MIA, CLT. Top destinations include Dallas-Fort Worth, Charlotte, Miami, Phoenix, Chicago.

5. United

1,059 outgoing routes from 131 airports in the United States to 225 destinations (123 domestic, 102 international). Busiest bases: DEN, IAH, EWR. Top destinations include Denver, Chicago, Houston, Newark, San Francisco.

6. Allegiant Air

887 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. Frontier

663 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.

9. 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.

10. Breeze Airways

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

11. PSA Airlines

461 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.