He tried rodeo riding for a few years. In 1982, he made his film debut as Tyler in Steven Spielberg’s E.T. the Extra-Terrestrial. Afterward, at 15, he was cast as the lead role Ponyboy Curtis in Francis Ford Coppola’s The Outsiders, which earned him a Young Artist Award.

When Howell was young, his parents divorced. Howell graduated from Saugus High School in 1984.

In 1984 he and Outsiders co-star, Patrick Swayze, reunited for Grandview, U.S.A., also with Jamie Lee Curtis, and Red Dawn, with Charlie Sheen and Lea Thompson. Howell also had a pivotal role in Tank, with James Garner and Jenilee Harrison. In 1985 he again starred in the lead role in Secret Admirer, opposite Lori Loughlin and Kelly Preston.

In 1986, he played a hitchhiker’s target in the film The Hitcher. The sequel, in which he also starred, was released in 2003. He starred as a white student who pretends to be black to receive a scholarship in the poorly received Soul Man, which currently holds an aggregated score of 14% at Rotten Tomatoes.

In 1988, Howell played the young Arturo Toscanini in the story of the world-renowned conductors debut in Franco Zeffirelli’s Giovane Toscanini with Irma Capece Minutolo and Elizabeth Taylor. The film was never released domestically.

Howell married actress Rae Dawn Chong in 1989, whom he met while co-starring with her in the 1986 film Soul Man. They divorced the following year in 1990. Howell married his second wife Sylvie Anderson, in 1992. Together, the couple had three children. In 2016, Anderson filed for divorce.

At the end of the 1980s and beginning of the 1990s, Howell appeared in The Return of the Musketeers and Side Out. In 1993, he starred with Linda Fiorentino and Nancy Allen in the campy thriller Acting on Impulse.

Howell has worked with Francis Ford Coppola many times and in other areas of making motion pictures including writing, producing, and directing. In 1995, he wrote and directed Hourglass, in which he starred with Sofia Shinas. The following year, he helped produce The Big Fall and Pure Danger.

He started an interest in crime-thrillers after starring in Payback and playing gangster Baby Face Nelson in a film of the same name. He went on to direct and star in the 1996 direct-to-video release, Pure Danger, featuring alongside Teri Ann Linn and prop comic, Carrot Top.

After Two Marriages, Howell made guest appearances in shows like Moonlighting and The Hitchhiker. In 2000, Howell played a doctor stranded on a deserted island after a plane crash in Amazon.

In 2005, he starred in H. G. Wells’ War of the Worlds, one of three 2005 adaptations of the novel The War of the Worlds by H. G. Wells. Howell directed and starred in a straight-to-DVD sequel War of the Worlds 2: The Next Wave in 2008.

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. After War of the Worlds, he spent time directing straight to-DVD films.

In 2006, Howell starred in Hoboken Hollow. He also became a supporter of the production company The Asylum, which produced his straight-to-DVD films.

Also in 2008, he directed and starred in The Day the Earth Stopped, a mockbuster intended to capitalize on The Day the Earth Stood Still.

In 2011, he guest starred as an inmate on The Glades and in Torchwood: Miracle Day.

Howell appeared in the 2012 film The Amazing Spider-Man.

Howell played the role of Officer Bill ‘Dewey’ Dudek, a police officer recovering from alcoholism, in the L.A. police drama Southland. He appeared in Seasons 1, 2, 3, and 4 and was promoted to a series regular for Season 5, which began in February 2013. The series was cancelled on May 10, 2013.

Starting in 2015, Howell has had a recurring role as Dr. Daniel Stinger in the Freeform show Stitchers. In 2017, he had a recurring role as Ash Spenser, a retired Navy SEAL, in the CBS show SEAL Team.

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.