Student Union, Student center in Stillwater, Oklahoma, US

The Student Union at Oklahoma State University is a multi-storey activity center on the Stillwater campus, built in 1950 and expanded in 1960, 1965, 2000, 2012 and 2016. Inside are the 81-room Atherton Hotel, the Ranchers Club restaurant, a 550-seat theater, a food court, bookstores, a recreation center and a post office.

The Student Union was built in 1950 and was the first union in the United States funded entirely by self-liquidating bonds. Five major expansions followed in 1960, 1965, 2000, 2012 and 2016, with an adjacent parking garage added in 1970. The building closed during the 2010–2011 academic year for renovation, when most student services moved to the Classroom Building basement and the temporary "UToo" building.

The building functions as a gathering place where students from different backgrounds meet through clubs and activities. Walking through reveals mixed-use spaces designed for socializing, studying, and attending events that define campus life.

The building is easy to find on campus and laid out in a way that helps you navigate it. Most areas are open to visitors and you can get basic services here including a hotel if you need overnight accommodation.

A hotel operates directly inside the building, which is unusual for a student center. This setup allows visiting families and guests to stay right in the middle of campus activity.