The fair place to meet is Chicago, IL — the city closest to the midpoint of Columbus and Milwaukee. From the farther side that’s about 5 hr 47 min of driving.
Recommended midpoint
Chicago, IL
From Columbus
5 hr 47 min
276 mi to Chicago
From Milwaukee
2 hr 2 min
81 mi to Chicago
Milwaukee has the shorter trip; the split is off by about 3 hr 45 min. The alternatives below can even it out. Columbus and Milwaukee are about 331 miles apart.
Columbus and Milwaukee are about 331 miles apart by road. Split the difference and you arrive near Chicago, the city closest to the halfway point between them. That puts roughly 5 hr 47 min of driving on the Columbus side and 2 hr 2 min on the Milwaukee side — the fairest single meeting point among the cities near the middle.
That's a half-day drive from each side, so Chicago suits an overnight or a weekend rather than a quick coffee — long enough to want a reason to stay, short enough to drive.
If Chicago doesn't have what you're after, Indianapolis and Detroit are also close to the midpoint and worth a look — each keeps the drive reasonably balanced between Columbus and Milwaukee.
Chicago is the most populous city in the U.S. state of Illinois and in the Midwestern United States. Located on the western shore of Lake Michigan, it is the third-most populous city in the United States, with a population of 2.74 million at the 2020 census. Read more →
Columbus is the capital and most populous city of the U.S. state of Ohio. With a population of 905,748 at the 2020 census, it is the 14th-most populous city in the U.S., second-most populous city in the Midwest, and third-most populous U.S. state capital. Read more →
Milwaukee is the most populous city in the U.S. state of Wisconsin. It is located on the western shore of Lake Michigan at the confluence of the Milwaukee, Menomonee, and Kinnickinnic Rivers. Read more →
City descriptions adapted from Wikipedia (CC BY-SA); photos via Wikimedia Commons, credited above.
Estimates use straight-line distance and typical road speeds; real drive times vary with route and traffic.