United · SEA
What gates does United use at Seattle Airport (SEA)?
United uses 25 gates at Seattle Airport (SEA), mainly in Concourses B, S and A, with about 30 departures a day (Oct 1–21, 2026). It is the main airline at 5 of them. By departures: Concourses B (87% of its departures), S (8%) and A (4%).
Based on 1,133 United flights at SEA, Oct 1–21, 2026 (full days)
How United compares at SEA
- 3rd of the 34 airlines with regular flights at SEA by departures: 5% of them (30 departures a day of about 587 a day).
- 6% of the seats leaving SEA: about 4,724 a day, 158 per departure.
- 1.2 turns a day at each gate it turns planes at, 74% fewer than the airport’s 4.5.
- Median turn at the gate: 75 min, the same as the airport median (75 min).
- 17% of its departures are regional jets, against 28% across SEA.
- At SEA, United’s 30 departures a day compare with American’s 26 and Southwest’s 24. United has 5 gates of its own; American 6; Southwest 3.
Where United flies nonstop from SEA
11 nonstop destinations. Nonstop routes seen Oct 1–21, 2026; a few days of data can miss weekly or seasonal routes.
| Destination | Flights | Other airlines on this route |
|---|---|---|
| San FranciscoSFO | 7/day | Alaska (8-9/day), Delta (5/day) |
| DenverDEN | 5-6/day | Alaska (4-5/day), Southwest (3-4/day), Delta (3/day), Frontier (1/day), American (under 1/week) |
| Chicago O'HareORD | 5/day | American (4-5/day), Alaska (4-5/day), Delta (3/day) |
| HoustonIAH | 4/day | Alaska (2/day) |
| Los AngelesLAX | 3-4/day | Alaska (9/day), Delta (6-7/day), American (3/day), Frontier (1/day) |
| NewarkEWR | 2-3/day | Alaska (3/day) |
| Washington DullesIAD | 2/day | Alaska (2-3/day), Delta (6-7/week) |
| Las VegasLAS | under 1/week | Alaska (8-9/day), Delta (4-5/day), Southwest (2-3/day), Frontier (4-5/week), American (under 1/week) |
| Minneapolis/St. PaulMSP | under 1/week | Delta (5/day), Alaska (2-3/day), Sun Country (4-5/week) |
| Salt Lake CitySLC | under 1/week | Delta (6-7/day), Alaska (4-5/day) |
| San JoseSJC | under 1/week | Alaska (5-6/day), Delta (4-5/day), Southwest (2-3/day) |
When United flies at SEA
- First departure of the day usually around 4:55 am, the last around 11:55 pm.
- Busiest hour: 11:00 pm–12:00 am, with about 5 of its arrivals and departures.
- About 7 of its aircraft spend the night at SEA (arrive in the evening, leave the next morning).
United’s aircraft at SEA
| Aircraft | Departures | Seats each |
|---|---|---|
| 737 MAX 9 | 8/day | 179 |
| 737 MAX 8 | 5-6/day | 166 |
| E175 | 5/day | 76 |
| A321neo | 3-4/day | 200 |
| 737-800 | 3-4/day | 166 |
| A320 | 2/day | 150 |
| 737-900 | 1-2/day | 179 |
| A319 | 6-7/week | 126 |
| 787-9 | under 1/week | 257 |
| 777-200 | under 1/week | 276 |
About 4,724 seats leave SEA on United each day. Of the gates it holds, 4 have taken a narrow-body and 1 only regional jets. Seats are capacity from each airline’s seat map per aircraft type, not passengers.
United’s gates at SEA
Concourse B B7A, B9, B11, B15, B21
Held = the airline flying the gate most (regional partners count as their brand).
Gates it shares
| Gate | Who holds it | Other airlines there |
|---|---|---|
| S1 | Common use | Delta, Alaska, Air Canada, Frontier |
| CG2 | Too few flights yet | – |
| MF2 | Too few flights yet | – |
| S2 | Common use | Delta, American, Alaska, Volaris |
| CG3 | Too few flights yet | – |
| S3 | Common use | Delta, Alaska, Volaris, JetBlue |
| S4 | Common use | Alaska, Delta, Icelandair, JetBlue |
| S5 | Common use | Delta, Air Canada, Aeroméxico, JetBlue |
| A6 | Held by Delta | Delta, Alaska, Air Canada |
| S6 | Common use | Delta, Alaska, Air Canada, Frontier |
| A7 | Common use | Delta, Alaska, Air Canada, American |
| S7 | Common use | Alaska, Delta, Japan Airlines, Virgin Atlantic |
| A8 | Common use | Delta, Alaska, Lufthansa, Korean Air |
| S8 | Common use | Alaska, Delta, Lufthansa, ANA |
| A9 | Held by Delta | Delta |
| S9 | Common use | Delta, British Airways, Alaska, Condor |
| S9A | Common use | Delta, Alaska, Southwest, American |
| A10 | Common use | Delta, China Airlines, Air France, Condor |
| S11 | Common use | Delta, Alaska, Lufthansa, STARLUX |
| D20 | Held by Alaska | Alaska, Sun Country |
About this data
Based on 16 full days of flights at SEA, Oct 1–21, 2026. Gates of its own are the gates where United flies the most (regional partners count as their brand). Every one of its departures has a seat count.
United at SEA: questions
What terminal is United at Seattle Airport (SEA)?
United flies from Concourses B, S and A at Seattle Airport (SEA). By departures: Concourses B (87% of its departures), S (8%) and A (4%).
What gates does United use at SEA?
United has 5 gates at SEA (the airline flying each one most): B11, B15, B21, B7A and B9. It used 25 gates in all over Oct 1–21, 2026.
How many flights a day does United have from SEA?
About 30 departures a day and 4,724 seats, averaged over Oct 1–21, 2026.
Where does United fly nonstop from SEA?
United flies nonstop to 11 cities from SEA, the most often to San Francisco, Denver, Chicago O'Hare, Houston, Los Angeles and Newark. Routes seen Oct 1–21, 2026.
When is United’s first flight out of SEA?
Usually around 4:55 am; the last leaves around 11:55 pm.
Does United share gates at SEA?
Yes: 20 gates it uses are shared or used most by another airline, e.g. gate S1 with Delta, Alaska, Air Canada and Frontier.
Other airlines at SEA
All of SEA’s gates by airline · United at every airport we map · Nonstop routes from SEA