Carl Patrick "Cubby" O'Brien, better known by his nickname Cubby, is an American drummer and former child actor. He is known as one of the original Mouseketeers on the weekday ABC television program The Mickey Mouse Club from 1955 to 1958.

The Mickey Mouse Club is an American variety television show that aired intermittently from 1955 to 1996 and returned to social media in 2017. Created by Walt Disney and produced by Walt Disney Productions, the program was first televised for four seasons, from 1955 to 1959, by ABC. This original run featured a regular, but ever-changing cast of mostly teen performers. ABC broadcast reruns weekday afternoons during the 1958–1959 season, airing right after American Bandstand. The show was revived three times after its initial 1955–1959 run on ABC, first from 1977 to 1979 for first-run syndication as The New Mickey Mouse Club, then from 1989 to 1996 as The All-New Mickey Mouse Club airing on The Disney Channel, and again from 2017 to 2018 with the moniker Club Mickey Mouse airing on internet social media.