While he was working a summer job as an usher at the Festival of America Theatre, a director spotted him and suggested he would make a great addition to his play's chorus.

In that company, Frakes did his first off-Broadway acting in Eugene O'Neill's The Hairy Ape directed by George Ferencz.

[11] When his character, Vietnam veteran Tom Carroll, was dismissed from the show, Frakes, urged by his agent, moved to Los Angeles, where he obtained guest spots in many of the top television series of the 1970s and 1980s, including The Waltons, Eight Is Enough, Hart to Hart, Barnaby Jones, The Dukes of Hazzard, Matlock, Quincy, M.E., and Hill Street Blues.

While appearing on the show, Frakes was allowed to sit in on casting sessions, concept meetings, production design, editing, and post-production, which gave him the preparation he needed to become a director.

[15][17] Frakes is also one of six Star Trek actors (the other actors being Kate Mulgrew, Michael Dorn, George Takei, Avery Brooks and Majel Barrett) to lend their voices to the video game Star Trek: Captain's Chair, reprising his role as Riker when users visit the Enterprise-E bridge featured in the game.

"[13] It was several years before Frakes was given another opportunity to direct for television, and Thunderbirds remains his final theatrical directorial credit.

Frakes also voiced Finn the Human's adult version in the episodes "Puhoy" and "Dungeon Train" on Adventure Time.

Frakes appeared on the 1994 Phish album Hoist, playing trombone on the track titled "Riker's Mailbox".

Frakes would occasionally perform on the trombone during his tenure as Commander Riker, drawing on his college marching band experience.

[18] In one episode, Frakes presented an interview of reporter Yolanda Gaskins with veteran astronaut Gordon Cooper, where they discussed the possibility of aliens having visited Earth in the past.

Frakes and Francis appeared together in Lois & Clark in the episode "Don't Tug on Superman's Cape" as a creepily too-good-to-be-true couple.

In addition to Roswell, Frakes has directed episodes of Leverage,[21] Castle, NCIS: Los Angeles, Burn Notice, Falling Skies and most recently Marvel's Agents of S.H.I.E.L.D., Switched at Birth, Hit the Floor, The Librarians, and The Orville.

[26] Frakes first met actress Genie Francis on the set of the television soap opera Bare Essence, and again while filming the mini-series North and South.