O'Hare layover: changing terminals and connection time

At O'Hare, the key question is which terminals. Terminals 1, 2 and 3 are joined inside security, so a connection between them is a walk. Terminal 5 is separate: it handles international arrivals, and getting to or from it usually means either riding the airport train and going through security again, or taking an airside transfer bus that only runs during the day. Customs for international arrivals is also in Terminal 5.

How much time does the airport say you need?

O'Hare doesn't publish a minimum connection time. For international arrivals it says many factors affect how long customs takes, but that it is rare for it to take more than two hours. On one ticket, your airline sold you a connection that meets its minimum and must rebook you if you miss it. Read is a 1-hour layover enough?

Connecting between Terminals 1, 2 and 3

If you arrive on a domestic flight and connect in Terminals 1, 2 or 3, you can walk between them without leaving the secure area. Follow the overhead signs; you don't need the train.

Connecting to or from Terminal 5

You have two options:

	Airport train	Terminal transfer bus
Inside or outside security	Outside: you go through security at your next terminal	Inside: no new security check
Hours	24 hours	11:30 a.m. to 9:30 p.m.
Who can use it	Anyone	Connecting passengers with a same-day boarding pass from the terminal they're going to
Stops	All terminals; about 10 minutes end to end	Terminal 1 (Gate C18B, moved for construction), Terminal 3 (Gates G17 and K20), Terminal 5 (Gate M13)

The bus runs between Terminals 1, 3 and 5.

Arriving from another country

International flights arrive at Terminal 5, where U.S. Customs and Border Protection is located:

Passport control. Follow the corridors to the processing area.
Claim all your bags, even if they're checked through, and take them through agriculture screening.
Recheck your bags at the counters just outside the customs area.
Then either:
- take the free airport train to Terminal 1, 2 or 3 and go through security there, or
- go through security in Terminal 5 and take the transfer bus (daytime hours only).

All connecting passengers go through TSA screening. Pack liquids in your checked bag before you recheck it. Duty-free liquids over 3.4 ounces only get through in a secure, tamper-evident bag.

Precleared flights (for example from Canada or Ireland) arrive as domestic flights. Some arrive in Terminal 5, where you can take the transfer bus to Terminals 1 or 3 without being rescreened; others arrive in Terminals 1–3. Read international to domestic connections.

What's changing

Terminal 1 construction: Gates B1 to B3 reopened in July 2026, while Gates C1 and C3 closed to build a bridge to a new satellite concourse, Concourse D, due in late 2028. The transfer bus stop moved to Gate C18B.
Check the terminal on your boarding pass on the day of travel.

Follow the first flight

Add both flights to FlyingOver before you travel. You'll follow the first flight offline and see its estimated arrival, and with Premium, connection guidance shows whether your layover looks comfortable, whether you need to keep moving or whether you should go directly to the gate.

Connecting at Chicago O'Hare: Terminals 1–3, Terminal 5 and customs