That person was Cleto Escobedo III, Kimmel’s lifelong best friend and eventual bandleader, who died Tuesday at 59 years old.

Jimmy Kimmel broke down in tears while paying tribute to his childhood best friend, Cleto Escobedo III, after his death Tuesday.

Mr. Escobedo’s band, Cleto and the Cletones, has been with “Jimmy Kimmel Live!” since the show’s inception in 2003, but his association with Mr. Kimmel dated to their time growing up together in Las V...