His first TV role was on the soap opera Another World, as Catlin Ewing, whom he played from 1984 to 1987. In 1999, he starred in the TV movie Secret of Giving with Reba McEntire; earlier in 1999, he had appeared in Reba's video for the song "What Do You Say". He also starred as Rock Hudson in a 1990 TV movie about Hudson's life for which he received critical acclaim. He has made guest appearances on a number of television shows, including In the Heat of the Night, Wiseguy, and One Tree Hill.

Griffith's first feature film was 1989's The Karate Kid Part III, in which he played Terry Silver, a rival martial arts expert who influences Daniel LaRusso against his friend and mentor, Mr. Miyagi.

Griffith is married to his former Another World costar Mary Page Keller since 1991, and has two children, Conner and Eamon. He holds black belts in kenpo karate and tae kwon do.

In 1996, Griffith starred in the film Hollow Point alongside Tia Carrere, as DEA agent Max Parish and FBI agent Diane Norwood respectively. In the film, they try to find a money launderer who hired a hitman (Donald Sutherland) to kill Diane's FBI partner in revenge for a wedding gone wrong, which resulted in the death of a Russian mobster's son. He also appeared in the 1998 John Carpenter film Vampires as head vampire Jan Valek, and in the 2002 film XXX, in which he portrayed Agent Jim McGrath.

Since 2013, Griffith periodically wrote and worked as a story Editor for the NBC television series Grimm and became a co-producer in 2015.