Charles Denton "Tex" Watson (born December 2, 1945) is an American convicted murderer who was a central member of the "Manson Family" led by Charles Manson. Watson is often described as the tactical ringleader of the Tate-LaBianca murders on August 9–10, 1969, when Watson, Patricia Krenwinkel, and Susan Atkins murdered pregnant actress Sharon Tate, Jay Sebring, Wojciech Frykowski, Abigail Folger, and Steven Parent at 10050 Cielo Drive in Benedict Canyon, Los Angeles. The next night, Watson traveled to Los Feliz, Los Angeles, and participated in the murders of Leno and Rosemary LaBianca. Watson was convicted of murder in 1971 and sentenced to death. As a result of a 1972 California Supreme Court decision on the constitutionality in the state of the death penalty, he avoided execution but has remained incarcerated ever since. Watson has been denied parole 18 times since he became eligible for parole in 1976 after his death sentence was commuted.

Watson was born in Dallas, Texas, on December 2, 1945, and grew up in nearby Copeville. He was the youngest of three children. Watson grew up attending church locally, and was an honor student, editor on the school paper, and captain of the football team, and set a record for the high hurdles at Farmersville High School. In September 1964, Watson moved to Denton, Texas, to attend the University of North Texas, where he became a member of Pi Kappa Alpha fraternity.

In January 1967, Watson began working at Braniff International as a baggage handler. When funds became low, he used free airline tickets he got as a perk of being a handler to visit an old fraternity brother in Los Angeles; there he became interested in the psychedelic music and lifestyle of the late 1960s. While driving one day, Watson picked up a hitchhiker, Dennis Wilson of the Beach Boys, and drove him to Wilson's house. There he was first introduced to the Manson Family who lived with Wilson.

Watson lived with the Manson Family at Spahn Ranch for nine months before the crimes, becoming close to Manson, and eventually choosing to believe Manson's lies and deception. According to Los Angeles County District Attorney Vincent Bugliosi, Manson employed “a variety of techniques" to accomplish this, and was able to bring Watson and others to conspire in following Manson’s delusion to ignite a massive race war (which Manson called “Helter Skelter”, inspired by the Beatles song of the same name) intended to bring in Manson's kingdom following this war.

In December 1968, Watson left the Manson Family. He moved in with a woman who sold small quantities of marijuana and LSD to his friends, and became her lover. The two lived in Hollywood for a few months, improving their illegal activity, until Watson became restless and rejoined the Family.

Following Manson's orders to "find money for Helter Skelter", Watson contrived to steal money from his lover's friend, Bernard Crowe. Crowe called the ranch, spoke to Manson and told him he would come to the ranch and kill everyone if he did not get his money back. In response, Manson shot Crowe in the stomach using the same pistol that Watson would use in the Tate murders.

The two encountered one another in the California Men's Colony in the early 1980s. Following a long conversation about the past and religion Crowe forgave Watson for his role in the theft and the shooting.

On August 9, 1969, as a member of the Manson Family, Watson led Susan Atkins, Linda Kasabian, and Patricia Krenwinkel to 10050 Cielo Drive, the home of Roman Polanski and Sharon Tate. They murdered all four people inside the house, and also Steven Parent in the driveway. Watson and his crime partners inflicted 28 stab wounds to one victim, Abigail Folger, alone.