I will be arriving on F9 1595 from Atlanta and my SO will be on UA1531 from Minneapolis. Where can we meet in ORD without getting lost and too much hassle?

There's no good answer to this one. F9 operates from T5 while UA is in T1 and T2. Importantly, T5 is a separate security zone. There are airside shuttle busses that go to/from T5 to T1 and T5 to T3 but... there are reports that they limit those to who have a boarding pass applicable to the other terminal. However, people have gotten past this by saying "I'm going to the lounge in T5 (or T1 or T3)" and they've been let on.

Are you terminating at ORD or going onward the same day? That may help answer your question.

We are both heading off to Chicago downtown.
Does it make sense and is it possible for him to come to T5 arrivals not airside? US flight arrives an hour earlier.

Yes. He can get his bags (if he has them), and hop on the train that goes between terminals. It will deposit him at T5, (See here.)
But if you are taking public transit (the L) downtown, it would be better for him to grab a bite at Tortas Frontera or something, and for you to head to T1-3 because the L platforms are there.

Many thanks, much appreciated!
Given the time of our arrival, traffic wise, is it better to take UBER or get on public transportation? We are staying close to Magnificent Mile.

Unless there is a great reason (really heavy bags, one of you is not as mobile), get on the L and take the Blue Line, most likely to State and Lake, where you'll probably get on the Red Line. Google Maps is very accurate for CTA transfers and such. An Uber will cost you a ton and possibly take longer (or as long) depending on traffic. At minimum take the L to the Loop and grab a taxi/uber from there, but depending on which hotel, chances are the Red Line will get you close enough. The price is $5.00, and you can tap and pay or download the Ventra app and buy a multiday pass, no need to stop at the machines. You do NOT have to tap out. The fare back to ORD is only $2.50, so $7.50 each for RT airport transport.

One note: Ubers have a designated pick up spot at ORD, and it's sometimes more of a pain to get there with bags than just get to the train. Should you want a paid ride, use the Curb app, which works like Uber/Lyft but is the taxi app. It's often lower or comparable.

Have a great time!

factors are

when are the flights get in? Dark outside?
where is the hotel? How close is it to the River.


in the map shared above it would be easier just to meet by the train near the Hilton/ rail station and have far less crowds. It just depends on luggage/ fitness.

https://ctagifts.com/products/chicag...rBiyj08sX6zwtR

the line from the airport take you downtown just over the river. Some of the hotels are just a few blocks from the stop.

In the end, with a perfect timing we met each other by Frontier carousel at T5, he got there by train.
And old good taxi to downtown, as Uber has pickups at T2.
Worked out perfectly, Chicago is amazing!