The body was found in the River Porter, just off Summerfield Street in the Ecclesall Road area, at around 3.45am.
She has not yet been formally identified, but police believe it to be 18-year-old Caroline Everest.
Caroline was last seen by her friends at Corporation nightclub, in Milton Street, Sheffield, at around 2.30am on Sunday.
A message left on flowers at the scene of the discovery read: “RIP Caroline. Another young life taken too early. Thoughts are with your family at this sad time.”
Another read: “RIP Caroline. Another angel gained its wings.”
Police have cordoned off Summerfield Street from its junction with Eccsall Road and Napier Street and surrounding footpaths.
There is also a large police presence in the area.
Officers are continuing to establish the circumstances surrounding her death and are appealing to anyone who may have seen Caroline in this location to come forward.
Caroline, a Sheffield Hallam University student, was white, 5ft 6ins tall, and of slim build. She was wearing a black dress with a black cardigan and wore her long dark hair in a low ponytail, and wears glasses. She was carrying a black handbag with a cream strap.
If you saw her, or have information that could help, call South Yorkshire Police on 101, quoting incident number 998 of November 22, 2015.