Frid is best known for the role of vampire Barnabas Collins on the first incarnation of the gothic U.S. cult television serial Dark Shadows. He went on to star in the movie House of Dark Shadows. During the run of the series, Frid starred in "Dial M For Murder." Immediately after Dark Shadows ended in 1971, Frid starred as Thomas Becket in "Murder in the Cathedral" and "Wait Until Dark." Prior to appearing on "Dark Shadows," Frid played the short term role of a psychiatrist on the CBS soap, "As the World Turns."
In 1973 Frid appeared in the TV movie The Devil's Daughter starring Shelley Winters, and the following year starred in Oliver Stone's directorial debut, Seizure (aka Queen of Evil). He took time off from acting and lived in Canada before returning to the theater in 1978.
Frid has returned to the Dark Shadows conventions - New York in August 2007, Burbank, CA in July 2008, and Elizabeth, New Jersey in August 2009. In 2010 he returned to the role of Barnabas in the Dark Shadows audio drama The Night Whispers.