In his early career, Cho attained recognition for his guest starring role in the fantasy television series Charmed.

In 1994, he toured nationally for a stage production of Maxine Hong Kingston's The Woman Warrior by the Berkeley Repertory Theatre.

[6][7][16] There, he appeared in Edward Sakamoto's The Taste of Kona Coffee in 1996 and in Euijoon Kim's film My Tired Broke Ass Pontificating Slapstick Funk in 2000.

Cho guest-starred on Charmed as the ghost of Mark Chao, one of leading character Piper Halliwell's most prominent love interests, in the episode "Dead Man Dating" in 1998; he indicated in 2024 that it was a role that he "gets asked about... all the time".

He had supporting roles in the science fiction comedy Evolution, directed by Ivan Reitman; Down to Earth; and Bowfinger.

In 2002, Cho had a starring role in the ensemble cast of Justin Lin's Better Luck Tomorrow, a drama focusing on the travails of a group of Asian Americans living in Southern California who are academically successful but socially discontented, and as a result engage in wantonly violent, criminal behavior.

It was well received by critics, with Elvis Mitchell of The New York Times describing Cho's character's "lazy magnetism of which he is charmingly aware".

[20] Later that year, the movie Big Fat Liar was released, in which Cho played a Hong Kong-based film director.

[6] Cho appeared in the July 2004 issue of KoreAm Journal and, in September 2006, was cast in NBC's new comedy The Singles Table, but the series never aired due to changes in scheduling and production.

Cho played helmsman Hikaru Sulu in J. J. Abrams's feature film Star Trek.

[37] Julie Anne Robinson, one of the directors and executive producers of Selfie, revealed in 2021 interviews that she strongly supported casting Cho and had to persuade "top to bottom of everybody in that chain" that he was the perfect choice for the role, which took considerable time.

In July 2022, when Cho was asked about his thoughts on the show's cancellation, he answered, "I'm still stunned to see how many people still love that series.

[44] In 2018, Cho starred in the film Searching, playing a man combing social media for clues to his daughter's disappearance.

[46] In April 2019, Variety reported that Cho had been cast as Spike Spiegel in a live-action version of the Cowboy Bebop series.

[52] In early August 2024, Cho voiced in the audiobook version of the romantic comedy book, Drop Dead, written by Lily Chu.

[55] Cho is the lead singer for Viva La Union (formerly known as Left of Zed),[56] a Los Angeles garage rock band composed of former Berkeley and USC students.

They have one album, self-titled, while their song "Chinese Baby" is on the Harold & Kumar Escape from Guantanamo Bay soundtrack.

The purpose of the project was to call attention to the lack of opportunities for Asian American actors in Hollywood.