In 1963, he appeared in the ABC medical drama Breaking Point in the role of four year old Mikey in the episode “The Gnu, Now Almost Extinct”. He also played little Billy Taft, the nephew of Dr. Richard Kimble, in the season one episode of The Fugitive, “Home is the Hunted” (1964).

In 1981, Howard formed The Kempsters, a new wave rock and roll group that was composed mostly of his friends who were neighbors with him on Kemp Street. In 1982, their original drummer, Mike “Spooner” Bauer, was replaced by Tony Rodriquez and the band played regularly at Madame Wong’s West. The band retired in 1983. Although The Kempsters never released an album while together, Howard has recently begun distributing No Brains At All, a CD featuring four tracks the band recorded in various studios, and seven tracks recorded live on October 17, 1982 at Madame Wong’s.

Clint Howard married Melanie Sorich on October 29, 1995. In 2017, it was announced that Clint had filed for divorce.

In 2003, Howard played Johnny Bark on Arrested Development in the season one episode “Key Decisions”, which was produced and narrated by his brother, Ron. He was seen in an episode of Married… with Children as a creepy janitor. He played a car thief/murderer in the season four Seinfeld episode “The Trip”. Howard played Creepy Rodney in the season one My Name Is Earl episode “Stole a Badge”, and he was a guest star in the season three episode of the NBC show Heroes “I Am Sylar”.

In 2015, Howard began creating one-of-a-kind snow globes that are occasionally featured on entertainment programs. He brought one with him for his appearance on The Tonight Show Starring Jimmy Fallon (with, as a guest, Howard’s niece Bryce Dallas Howard).

Howard is a Republican (contrasting with his brother, Ron, a Democrat). On January 29, 2016, three days before the Iowa Caucuses, he endorsed United States Senator Ted Cruz of Texas for the Republican presidential nomination.