Chicago O’Hare airlines and terminals are worth learning before you fly. ORD is a massive U.S. hub linking the Midwest to North America, Europe, Asia, and the Middle East. United and American anchor domestic and long-haul traffic, while many international carriers operate from the modernized Terminal 5. This guide walks you terminal by terminal so you know where to check in, connect, and transfer efficiently.
Overview of Airlines and Terminals at Chicago O’Hare (ORD)
O’Hare has four passenger terminals used today: Terminal 1, Terminal 2, Terminal 3 (largely domestic plus some international departures) and Terminal 5 (primarily international). Terminals 1–3 are connected airside/landside by pedestrian walkways; Terminal 5 is linked by the Airport Transit System (ATS) and terminal transfer buses. The official airport map and airline location directory are updated regularly and should be your source of truth on day-of travel.
Terminal 1
Home base for United, with A/B concourses plus the C concourse satellite. Most United domestic and many United international departures leave here; select Star Alliance partners also depart here and arrive internationally at T5 for customs.
- Main airlines: United (domestic & some international departures), ANA (departures), Lufthansa (departures)
- Notes: United hub operations; easy walkway connections to T2/T3 airside for certain connections.
| Category | Details |
|---|---|
| Main Airlines | United; ANA (dep.); Lufthansa (dep.) |
| Gates | Concourses A, B, C |
| Transfers | Walkways to T2/T3; ATS to T5 |
Terminal 2
Mixed-carrier terminal bridging T1 and T3. Hosts United Express and several domestic carriers; some airlines here also use T5 for certain operations.
- Main airlines: United/United Express, Air Canada, Alaska, JetBlue, Southern Airways Express, Spirit (select ops)
- Notes: Short walk to T1/T3; use ATS or transfer bus for T5.
| Category | Details |
|---|---|
| Main Airlines | United Express, Air Canada, Alaska, JetBlue, Southern Airways Express, Spirit (some) |
| Gates | Concourses E, F |
| Transfers | Walkways to T1/T3; ATS to T5 |
Terminal 3
American Airlines’ primary home at ORD, with oneworld partners also using the terminal for departures. Domestic network is extensive; some international departures leave from T3 and arrive at T5.
- Main airlines: American (domestic & some international departures), Aer Lingus, British Airways (departures), Iberia (departures), Japan Airlines (departures), Contour
- Notes: Large footprint (G, H, K, L concourses). Walk to T1/T2; ATS to T5.
| Category | Details |
|---|---|
| Main Airlines | American; Aer Lingus; British Airways (dep.); Iberia (dep.); JAL (dep.); Contour |
| Gates | Concourses G, H, K, L |
| Transfers | Walkways to T1/T2; ATS to T5 |
Terminal 5
Modernized international gateway (Concourse M) hosting most non-United/non-American international carriers, plus several U.S. airlines now based here. All international arrivals requiring customs generally come into T5.
- Main airlines (examples): Delta, Frontier, Southwest; plus Aeromexico, Air France, Air India, Air New Zealand, Air Serbia, Austrian, Avianca, Cathay Pacific, China Eastern, Copa, Emirates, Ethiopian, Etihad, EVA, Finnair, Icelandair, ITA, JAL (arrivals), KLM, Korean Air, LOT, Lufthansa (arrivals), Qatar, Royal Jordanian, SAS, SWISS, TAP, Turkish, VivaAerobus, Volaris, WestJet (and more)
- Notes: Use the ATS from T1–T3 to reach T5; allow extra time for passport control on arrival.
| Category | Details |
|---|---|
| Main Airlines | Broad mix of international carriers; U.S. carriers incl. Delta, Frontier, Southwest |
| Gates | Concourse M (M gates) |
| Transfers | ATS to T1–T3; terminal transfer buses airside for select connections |
Airlines and Terminal Assignment Table (Quick Look)
| Airline | Primary Terminal |
|---|---|
| United | Terminal 1 (some international departures; many international arrivals at T5) |
| American | Terminal 3 (some international departures; arrivals at T5) |
| Air Canada | Terminal 2 |
| Alaska | Terminal 2 |
| JetBlue | Terminal 2 |
| Spirit | Terminal 2 / Terminal 5 (varies by flight) |
| Delta | Terminal 5 |
| Southwest | Terminal 5 |
| Frontier | Terminal 5 |
| Aer Lingus, British Airways, Iberia, JAL (dep.) | Terminal 3 (international arrivals at T5) |
| Most non-U.S. international carriers (e.g., Emirates, Qatar, KLM, Lufthansa arrivals, Turkish, SWISS, LOT, etc.) | Terminal 5 |
Ground Transportation & Terminal Transfers
Use the ATS (Airport Transit System) to move between all terminals, parking, and the rental car/Multi-Modal Facility. Terminals 1–3 are also connected by pedestrian walkways airside/landside. For connections to Terminal 5, plan for ATS travel time and security re-screening if changing between domestic and international zones.
- To downtown: CTA Blue Line from the pedestrian tunnel level (to The Loop)
- Rideshare/taxi: Clearly signed pickup zones outside terminal levels
- Rail & buses: Multi-Modal Facility hosts rental cars, regional buses; ATS connects directly
Essential Pre-Flight Tips
- Always verify your terminal on your airline app/boarding pass before heading out, assignments can change.
- For international trips, arrive earlier and allow time to reach Terminal 5 and clear exit/entry formalities.
- If you’re connecting between T1–3 and T5, budget extra transfer time via ATS and re-screening if required.
Final Boarding Thoughts
With United and American anchored in Terminals 1–3 and most international carriers flowing through Terminal 5, Chicago O’Hare’s layout becomes simple once you match your airline to the right building. Double-check your terminal in the airline app on the day of travel, allow a little extra time if you need the ATS to reach T5, and follow the overhead signs for the fastest security and transfer routes. Do that, and your ORD experience will feel organized, predictable, and connection-friendly from curb to gate.