Austin Bice was last seen Feb. 26 leaving a nightclub.
The 22-year-old's roommates reported him missing after he didn't return home.
Officials said Bice's body was found in a shallow part of the Manzanares River near the nightclub.
The cause of death hasn't been determined, but investigators found no signs of foul play, according to a National Police official.
Bice had been studying international business since January at Carlos III University in Spain.
