Manhattan, KS had about 50k people when I lived there years ago. It seems to have 52k now. Between students, faculty and staff, the university probably accounts for at least 40% of the population and sometimes over half.
It was one of the best experiences of my life. Terrific little town.
https://en.m.wikipedia.org/wiki/Manhattan,_Kansas
I think Athens, Georgia was about 100k people 40 years or so ago and is now 125k. It is home to UGA, one of the big two universities in the state. It's also a source of some big name bands, like R.E.M.