The Ohare Airport has a somewhat goofy layout. There are 4 terminals, 1,2,3, and 5. (Terminal 4 closed in the 90s). Terminals 1-3 are all connected airside, you can walk between all those terminals without exiting the secure area. Terminal 5 is geographically far away and you cannot walk to it from the other terminals.
Bottom Line: If you need to transfer to or from Terminal 5 at ORD, the Transfer Bus is likely the easiest and fastest option. Just keep in mind it requires a departing boarding pass and only runs between 11:30 am and 9:30 pm.
ORD Airport Layout
As you can see from the map, ORD Terminals 1-3 are somewhat close to each other. It’s easy to walk between all of them without re-clearing TSA. Terminal 5 is somewhat far away and you cannot just walk there.
To get to ORD Terminal 5 to/from the other terminals, you have two options. Either exit security and take the ATS(Airport Transit System) then re-clear security at your destination. Or you can take the Terminal Transfer Bus that runs between Terminal 5 and 1/3. The ORD Terminal 5 Transfer Bus requires you to show a boarding pass for a departing flight. The ATS runs 24 hours a day while the Transfer Bus operates between 11:30 am and 9:30 pm.
Using The ORD Terminal 5 Transfer Bus
When Val and I were returning from Amsterdam, Val and I used the bus to transfer from Terminal 5 to Terminal 3. To use the Terminal 5 Transfer Bus, look for the Express Connections signs.
In Terminal 1 near Gate B1, Terminal 3 Gates G17 and K20, and Terminal 5 Gate M13. Inside there is a person who checks you have a boarding pass and then directs you down to wait for the bus.
There’s a waiting area that has different doors. Each door and line is for a different bus to each of the different terminals.
Soon our bus arrived and we were escorted onboard. They confirmed our boarding passes again. It seems like there was more security and baby sitting than I would have expected for just a terminal bus transfer.
Onboard, the bus was pretty standard. There’s a luggage rack for carry on items.
Once we arrived at Terminal 3, we were escorted into the terminal by an agent. We went through was seemed like a back door and up some stairs. I now kinda understand why they were escorting us, this part of the process isn’t very polished.
ORD Terminal 5 Transfer Bus Final Thoughts
If you need to transfer between Terminal 5 and the other Terminals at ORD, the transfer bus is likely the fastest and easiest option. If it’s between 11:30 and 9:30 pm, you can avoid leaving security, taking the ATS, and re-clearing security by taking the bus. Just remember, they will check your boarding pass so don’t try to use the transfer bus just to visit a lounge or explore the airport.