He has starred in the films The Outsiders (1983), Red Dawn (1984), Secret Admirer (1985), Soul Man (1986), A Tiger's Tale (1987), and Young Toscanini (1988).

[9] Howell played the lead role of Ponyboy Curtis, "the soulful tagalong greaser through whose eyes we see the events of the 1960s-set film unfold.

After filming The Outsiders, Howell co-starred in his own television series Two Marriages, which ended after four episodes, but letters of support got it back on air.

[16][better source needed] Howell was one of two final actors in the running for the lead role of Marty McFly in Back to the Future (1985); the other was Eric Stoltz.

In 1993, Howell starred with Linda Fiorentino and Nancy Allen in the campy thriller Acting on Impulse.

Next, he starred as Mike, a motorcycle courier in the poorly received Mad Dogs and Englishmen (U.S. title: Shameless) with Elizabeth Hurley.

He directed and starred in the 1996 direct-to-video release Pure Danger, which also featured Teri Ann Linn and comic Carrot Top.

In 2000, Howell played a doctor stranded on a deserted island after a plane crash in the television show Amazon.

[18] Also in 2005, he reunited with his Secret Admirer co-star Lori Loughlin when he had a recurring role on her television show Summerland as Zac Efron's father.

[citation needed] In 2011, Howell guest starred as an inmate on The Glades and in Torchwood: Miracle Day.

In 2016 and 2018, Howell had a recurring guest-star role as Paul Belmont, a United States Navy Lieutenant Commander at Camp Pendleton, in Seasons 1 and 3 of Animal Kingdom.

[23] In 1989, he married actress Rae Dawn Chong, whom he met while co-starring with her in the 1986 film Soul Man.

[26] In November 2001, Howell was acquitted of five misdemeanor charges, including hit and run and brandishing a weapon arising out of a confrontation with a skateboarder in Southern California.