A Texas native, Mark Harelik is an American actor and playwright, popularly known for his work on American television and theatre. Beginning his career in the early 1980s, Harelik made his mark as an outstanding theatre artist and playwright winning several awards. In 1984, he won the Drama Logue Award for Outstanding Performance for his work in the play "Moby Dick-Rehearsed". Four years later, he went on to win Drama Logue Award for Outstanding Performance in "Lost Highway-The Music and Legend of Hank Williams. For the same play, Langham also won the Drama Logue Award for Outstanding Writing.

Harelik has primarily been active on American television appearing in TV shows such as Snowfall (2017), Preacher (2016), Imposters (2017), The Mentalist (2014), and Castle (2012). In 2018, he appeared in the movie Battle of the Sexes directed by Jonathan Dayton and Valerie Faris.