Born in Dallas, Texas, into a family of Mexican ancestry, Trevino was raised by his mother, Juanita Trevino, and his grandfather, Joe Trevino, a gravedigger. Trevino never knew his father, Joseph Trevino, who left when his son was small. Trevino's childhood consisted of attending school occasionally and working to earn money for the family. At age 5, he started working in the cotton fields.

At age 49 in the 1989 Masters, Trevino shot an opening round five-under-par 67 to become the oldest man ever to lead the field after a round in the tournament. It came despite Trevino's words 20 years earlier, when he said after the 1969 Masters: "Don't talk to me about the Masters. I'm never going to play there again. They can invite me all they want, but I'm not going back. It's just not my type of course." Trevino said that he felt uncomfortable with the atmosphere at the Augusta National club and that he disliked the course because his style of play, where he liked to fade shots left to right, was not suited to the course.  Trevino did not accept invitations to the Masters in 1970, 1971 and again in 1974. In 1972, after forgoing the previous two Masters tournaments, he stored his shoes and other items in the trunk of his car, rather than use the locker room facilities in the clubhouse. Trevino complained that had he not qualified as a player, the club would not have let him onto the grounds except through the kitchen. But he later described his boycott of the Masters as "the greatest mistake I've made in my career" and called Augusta National "the eighth wonder of the world."  After his opening round of 67 in the 1989 Masters, Trevino finished the tournament tied for 18th place. His best finish at the Masters was a tie for 10th place twice: in 1975 and in 1985.

Why did he want to go back?