Gil Grissom

Gilbert Arthur "Gil" Grissom, Ph.D. is a fictional character on the CBS crime drama CSI: Crime Scene Investigation, portrayed by William Petersen. Grissom was a forensic entomologist and the night shift supervisor of the Clark County, Nevada CSI (forensics) team, investigating crimes in and around the city of Las Vegas. He was the show's protagonist from seasons one to nine, when Petersen left the show as a regular, and was replaced by Laurence Fishburne as Raymond Langston, M.D.. He appeared in 198 episodes.

CSI: Crime Scene Investigation producer and writer Carol Mendelsohn considers Grissom the center of the show, and in the first seven years of the show, he appeared in every episode, with the exception of "Hollywood Brass", from season five, "Gum Drops" and "The Unusual Suspect" from season six, and "Sweet Jane" and "Redrum" from season seven. In late season six, it is revealed that he has become romantically involved with subordinate CSI Sara Sidle.

Grissom has received positive responses from critics, ranking number 82 on Bravo's 100 Greatest TV Characters list, along with Catherine Willows. He was ranked at number 9 on Sleuth Channel's poll of America's Top Sleuths.AOL TV named him one of TV's Smartest Detectives. Grissom's final episode as a regular drew over 23 million viewers.