A 26-year-old woman reported she had been attacked at the Great John Street Hotel in the northwest English city of Manchester in the early hours of Tuesday.
Extensive media reports said some of the team's players and their guests had gone to the hotel as part of the annual Christmas party.
"A 19-year-old man was arrested on suspicion of rape on Tuesday evening after presenting himself to police," a spokeswoman for the Greater Manchester Police force said in a statement. "He has been bailed until 23 February 2008 pending further inquiries." No charges have been laid.
A hotel spokeswoman said the premises were closed to the public but were likely to reopen on Wednesday. Television footage showed a number of police vehicles parked outside.
"We have had an allegation at the hotel and we are helping police with their investigation," she said.
A spokeswoman for Manchester United said the club was not commenting on the reports and was unlikely to do so.
