Taking a lap around the state, the Ohio airports with/which could have scheduled service we primarily chat in these threads include:
-CVG (Cincinnati/Northern Kentucky International Airport)- DL Hub/Focus City, G4 & F9 Focus City, large DHL/soon-to-be major Amazon Air hub, PSA MX & crew base. (Yes, it's in Kentucky, but it's Cincinnati's airport.

--LUK (Cincinnati Municipal Lunken Airport)- Home of Ultimate Air Shuttle.
-CMH (John Glenn Columbus International Airport)- Home of NetJets, Republic MX & crew base, Envoy MX base.
--LCK (Rickenbacker International Airport (Columbus))- Rapidly-developing international air cargo/logistics center, also served by G4.
-DAY (James M. Cox Dayton International Airport)- Home of PSA Airlines with a large MX and crew base, also houses an Air Wisconsin MX base.
-TOL (Toledo Express Airport)- Served by G4 and AA, gained service to CLT last year.
-CAK (Akron-Canton Airport)- Serves its own region and also acts as a secondary Cleveland airport.
-YNG (Youngstown-Warren Regional Airport)- No scheduled service now, but working on regaining passenger service.
-ILN (Wilmington Air Park)- Home of ABX/ATSG, dormant-but-soon-to-be-reactivated hub/sort facility for Amazon Air.
-HTS (Tri-State Airport, Huntington, WV)- Regional airport which serves southern Ohio, located across the Ohio River from Ironton.
-PKB (Mid-Ohio Valley Regional Airport, Parkersburg, WV)- EAS-served regional airport which serves Southeast Ohio and advertises itself as an airport for Marietta.
While CVG and CMH generate a good bit of the discussion, there's also talk in this thread about the smaller airports, and that's the intended beauty of these threads- a community stream to keep track of what's going on in and around the state. If you find something interesting about a non-commercially served airport, again, share it! In recent years, we've also "adopted" airports in West Virginia which are a stone's throw from Ohio (HTS and PKB).
Previous threads:
-2018- viewtopic.php?f=3&t=1382407&hilit=cle
-2017- viewtopic.php?f=3&t=1351523
-Part 5- viewtopic.php?f=3&t=607803
The reason we don't specifically include CLE in this series of threads is they've long had their own discussion (and, if memory serves, theirs came first and this was a response/supplement to that for the other airports). The newest CLE thread isn't up as of the time of this post, but the 2018 (for the moment, current) one is here: viewtopic.php?f=3&t=1382405&p=20967097&hilit=cle#p20967097 If you'd like to chat CLE here, however, feel free!