The fair place to meet is Dallas-Fort Worth, TX — the city closest to the midpoint of Memphis and San Antonio. From the farther side that’s about 8 hr 48 min of driving.
Recommended midpoint
Dallas-Fort Worth, TX
From Memphis
8 hr 48 min
420 mi to Dallas
From San Antonio
5 hr 18 min
252 mi to Dallas
San Antonio has the shorter trip; the split is off by about 3 hr 30 min. The alternatives below can even it out. Memphis and San Antonio are about 632 miles apart.
Memphis and San Antonio are about 632 miles apart by road. Split the difference and you arrive near Dallas, the city closest to the halfway point between them. That puts roughly 8 hr 48 min of driving on the Memphis side and 5 hr 18 min on the San Antonio side — the fairest single meeting point among the cities near the middle.
That's a half-day drive from each side, so Dallas suits an overnight or a weekend rather than a quick coffee — long enough to want a reason to stay, short enough to drive.
If Dallas doesn't have what you're after, Houston and Austin are also close to the midpoint and worth a look — each keeps the drive reasonably balanced between Memphis and San Antonio.
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 →
Memphis is a city in Shelby County, Tennessee, United States, and its county seat. Read more →
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 →
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.