Mark Sargent is an American figure known for his advocacy of the Flat Earth theory. He gained prominence through his YouTube channel, where he shares videos discussing his beliefs about the shape of the Earth and related topics. Sargent often presents arguments that challenge mainstream scientific views. In addition to his online presence, Sargent has participated in various podcasts and interviews, promoting the Flat Earth movement. He has also produced documentaries that explore his perspective on the Earth's shape and the implications of questioning established scientific consensus.