Brian Stack

Stack continued his work on O'Brien's TBS series, Conan. His last episode aired on April 2, 2015. In the episode, he appeared as The Interrupter, one of his recurring characters, in a sketch in which he and his character bade farewell to the series.

Stack was born in Chicago, Illinois. He attended Catholic schools from grades 5–12, graduating from St. Viator High School in Arlington Heights, Illinois. He earned an undergraduate degree from Indiana University, where he was inducted into Phi Beta Kappa. He worked at the college radio station and drew cartoons/illustrations for the Indiana Daily Student. He began doing improvisational comedy, or improv, in 1987 at the Ark Theater in Madison, Wisconsin, while attending graduate school at University of Wisconsin–Madison.

Stack remained with O'Brien after O'Brien's move to The Tonight Show in 2009. Stack played many recurring characters on the show, most notably those clad in anachronistic or elaborate outfits, and was known for playing many characters with long beards and mustaches, such as God, Zeus, Socrates, Gandalf, Dumbledore, and The Interrupter. Jeff Loveness of Jimmy Kimmel Live has observed of Stack's characters that there was "such a sadness to each character, but they would not acknowledge their sadness", an assessment that Stack agrees with. Stack has further explained that, "My favorite kind of comedy on the late-night has always been the non-topical silly stuff where it's not really at anybody's expense. My least favorite kind of joke is a celebrity joke, because it tends to be very familiar or sometimes very mean, and if it's not mean it doesn't even work, usually...But my favorite kind of comedy on late night is at no one's expense but the character that's involved in the sketch where you're not really going after anybody." Stack made occasional appearances on The Tonight Show, such as when he played an NRA spokesman who intimates violence to accomplish his agenda.

Stack became a sketch writer on Late Night with Conan O'Brien in 1997, and served as a writer and actor on the show. He first appeared onscreen when one of the writers asked him to play a doctor in a sketch in which he had no dialogue. One of the first characters he did on the show was Bathtime Bob the Hygiene Cowboy, who sang about bath time, but like many of Stack's characters, he had a very dark, tragic underbelly to his upbeat nature. Stack had previously tried to develop this character at Second City, but it never appeared in any shows.

Brian Stack (born August 18, 1964) is an American actor, comedian, and writer best known for his sketch comedy work on all three Conan O'Brien late-night talk shows, previously working on Late Night with Conan O'Brien and The Tonight Show with Conan O'Brien, and on O'Brien's current talk show, Conan on TBS. Stack left Conan in April 2015 to join the writing staff of the CBS series The Late Show with Stephen Colbert.