Peter Grant is a character on DEXTER. He was the boyfriend of Holly Benson, one of the attempted victims of the Doomsday Killers.

Dexter discovered Holly's relationship with Grant and went to his house.on the hunch that he might lead him to Travis Marshall, At the house's gate, Dexter was met with Grant's daughter who revealed that she knew of Holly and Grant's relationship and stated, with little certainty, that Grant was either in Spain or Portugal,. Grant's daughter also tells Dexter that Holly might be staying on Grant's yacht, the Ricochet Rabbit, which acted as Grant's "fuck pad".

Meanwhile, Holly, who had been given access to the boat while Grant was away, is cornered on the boat by Travis and two of his followers before being brutally murdered by them. Dexter, after posing as Grant on the phone to get the boat's location, later arrives at the Ricochet Rabbit where he finds Travis' follower, Steve Dorsey, preparing the Wormwood attack. After a struggle, Dexter kills Steve and finds Holly's corpse. 

The episode in which Peter Grant is mentioned, Episode 610: Ricochet Rabbit, is named after Grant's yacht.