Mark Edward Fischbach ( FISH-bahk; born June 28, 1989), known online as Markiplier, is an American YouTuber and film director. He mainly uploads gaming content. After joining YouTube in 2012, Fischbach quickly established himself on the platform with Let's Plays of survival horror games such as Amnesia: The Dark Descent (2010) and the Five Nights at Freddy's series. As of June 2023, his channel has over 35 million subscribers.After expressing an interest in more traditional entertainment, Fischbach signed with talent agency William Morris Endeavor in 2016. In the following years, he started a live tour, a clothing line named Cloak, wrote and directed the YouTube Original series A Heist with Markiplier (2019) and In Space with Markiplier (2022), and several podcasts—two of which reached No. 1 on Spotify. In 2023, Fischbach moved to United Talent Agency. In April 2023, Fischbach announced he was leading production of the horror film Iron Lung, which will be his theatrical film debut.

Fischbach is one of the most popular gaming YouTubers on the platform. He was listed by Forbes as the third highest-paid content creator on the platform in 2022, and has won four Streamy Awards and a Golden Joystick Award for "Best Streamer/Broadcaster".