Samuel Monroe Jr. (November 28, 1973 – August 26, 2026) was an American actor and rapper under the name Caffeine. He acted in numerous films including Menace II Society (1993), Tales from the Hood (1995), Set It Off (1996), and The Players Club (1998), and appeared in television series including Out All Night (1993), and NYPD Blue (1996).

Monroe was also a rapper and performed as Caffeine. He was a part of the group Da Hoodstas alongside Drano and Lil D with whom he released an album called "Hoodsta Madness" in 1994 under Strictly Lethal Records. In 2000, he released his only solo album Things In The Game Done Changed, under Jive Records, Zomba Records and Goodfellas Entertainment. The album featured many notable artists including Kurupt, Noreaga and Too Short, as well as production from Battlecat and Jazze Pha among others.