Hu has had recurring roles as Pearl on The CW series The Vampire Diaries, Hamato Miwa / Karai on Teenage Mutant Ninja Turtles, Stacy Hirano on the Disney Channel animated series Phineas and Ferb, and as Adira in Rapunzel's Tangled Adventure.

Hu has mentioned in interviews that her mother had told her America was not ready for an Asian as such a prominent role model.

Hu modeled in Japan and Italy and became well known in the latter as the star of a series of television advertisements for Philadelphia brand cream cheese, playing a young Japanese college student named Kaori.

Hu moved to Los Angeles and began her acting career in 1987, with a guest starring role as Mike Seaver's Hawaiian love interest on the sitcom Growing Pains.

Hu followed this with appearances on various television series, including Night Court, Tour of Duty, 21 Jump Street and Melrose Place.

In January 2007, Hu began appearing in a full-time role on the television series In Case of Emergency.

In April 2009, Hu developed the character JIA for Secret Identities: The Asian American Superhero Anthology.

In 2012, Hu was cast in the role of Karai in the animated series Teenage Mutant Ninja Turtles.

Yeah, I don't know why people think I'm dangerous, but for some reason, I keep getting these roles for the ninja, assassin, bodyguard, bad-girl type.

In a personal first, she lent both her face and voice to the in-game character Khai Minh Dao in Battlefield Hardline, who partnered alongside the protagonist in roughly half of the game levels.

In 2007, Hu was a driver in the Toyota Pro/Celebrity Race, a national fund-raising program supporting children's hospitals throughout the United States.

[16] In April 2011, Hu was a celebrity host for Save the Children's "Caring for Japan's Keiki," a benefit for Japanese earthquake and tsunami victims.

[23] In February 2008, Hu also appeared in another viral video in support of Obama, "Sí Se Puede Cambiar", written and performed by Andrés Useche, directed by Eric Byler.

She supported[28] Reef Check Hawaii[29] by running in and successfully completing the Honolulu Marathon to raise awareness for the organization.