Robert "Bob" Harper (born August 18, 1965) is a personal trainer, who appears on the television series The Biggest Loser (United States) as the trainer for the blue team. He was also a trainer on the Australian version of the show in its first season.
Harper has worked as a personal trainer for several celebrity clients, including Jennifer Jason Leigh. He is featured as a trainer on the United States version of The Biggest Loser reality television series, and appeared on the first and third seasons The Biggest Loser:Australia. Harper also participated in The Biggest Loser DVD workout series.