Brett Clifford Gelman is an American actor and comedian. A prolific television actor, he is best known for his role as Murray Bauman in Netflix's horror-supernatural hit series Stranger Things and as Martin on the BBC comedy Fleabag.

Gelman began his career as a comedian in the 2000s, gaining notability the following decade for his involvement in numerous Adult Swim shows, notably Eagleheart and comedy specials in 2014 and 2015. During this time, he also was part of the main casts of the NBC sitcom Go On, the Comedy Central series Another Period, and the FX comedy series Married.

Gelman became prominent in the late 2010s for his critically acclaimed supporting roles in Fleabag and Stranger Things, in addition to those on Camping and Mr. Mercedes. As a voice actor, he has contributed to television series Jeff & Some Aliens and TripTank on Comedy Central and, more recently, I Heart Arlo and Inside Job on Netflix, among others. He is set to start in the upcoming drama series Lady in the Lake.