Bart McCarthy played Admiral Cobum in the Star Trek: Deep Space Nine sixth season episode "Favor the Bold". He also voiced Zashar in Star Trek: Starfleet Academy.
His first movie appearance was Memorial Day (1998, co-starring Jeffrey King, Rob LaBelle and Stephanie Niznik). He also played an uncredited role as a mental patient in Rat Race (2001, starring Whoopi Goldberg), and played Captain Bart the Pirate in The SpongeBob SquarePants Movie (2004, with Clancy Brown, Dylan Haggerty, Kristopher Logan and Paul Zies).
McCarthy also guest-starred in an episode of Angel (starring Scott Klace, L.L. Ginter, and Joel Polis), Babylon 5, Heroes (2007, starring Greg Grunberg and Zachary Quinto, with Cristine Rose, Jack Guzman, George Takei, Malcolm McDowell, and Dan Warner), Sons of Anarchy (2010–2013), and Silicon Valley (2015, with Matt McCoy). In 2017 he appeared in an episode of Baskets featuring Mary Wiseman.