Mikel Harris, 43, of San Francisco, was arrested Friday and booked into jail on a homicide charge.
Fluker was found wounded inside the hotel, located in the first block of Turk Street, shortly after 1 p.m. Friday. He was pronounced dead at San Francisco General Hospital.
The medical examiner's office has not yet confirmed Fluker's city of residence.
Police have not released information about the circumstances of the stabbing, or a possible motive.
The stabbing is the 17th homicide reported this year by San Francisco police.