The fair place to meet is San Antonio, TX — the city closest to the midpoint of Austin and Dallas. From the farther side that’s about 5 hr 18 min of driving.
Recommended midpoint
San Antonio, TX
From Austin
1 hr 50 min
74 mi to San Antonio
From Dallas
5 hr 18 min
252 mi to San Antonio
Austin has the shorter trip; the split is off by about 3 hr 28 min. The alternatives below can even it out. Austin and Dallas are about 182 miles apart.
Austin and Dallas are about 182 miles apart by road. Split the difference and you arrive near San Antonio, the city closest to the halfway point between them. That puts roughly 1 hr 50 min of driving on the Austin side and 5 hr 18 min on the Dallas side — the fairest single meeting point among the cities near the middle.
At this range, San Antonio works for a same-day meetup: close enough from both Austin and Dallas to meet for lunch or an afternoon and still be home by evening.
If San Antonio doesn't have what you're after, Houston and Oklahoma City are also close to the midpoint and worth a look — each keeps the drive reasonably balanced between Austin and Dallas.
San Antonio is a city in the U.S. state of Texas. It is the seventh-most populous city in the United States, the second-most populous city in Texas, and the second-most populous city in the Southern U.S., with a population of 1.43 million at the 2020 census. Read more →
Austin is the capital city of the U.S. state of Texas. With a population of 961,855 at the 2020 census, it is the 12th-most populous city in the U.S., fifth-most populous city in Texas, and second-most populous U.S. Read more →
Dallas is a city in the U.S. state of Texas. Located in the state's northern region, it is the ninth-most populous city in the United States and third-most populous city in Texas, with a population of 1.3 million at the 2020 census. 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.