Mark Williams may refer to:
- Mark Williams (writer) (born 1951), academic, writer, critic, poet
- Mark Williams (singer) (born 1954), New Zealand singer
- Mark Williams (actor) (born 1959), British actor and comedian
- Mark Williams (organist) (born 1978), Informator Choristarum at Magdalen College, Oxford
- Mark Williams (radio host), American journalist and radio personality
- Mark "Slave" Williams, hip hop MC, television presenter
- Mark Williams (game designer), original artist at Hero Games
- Mark Williams (Holby City), fictional character in Holby City
- Mark Williams (filmmaker), American producer, director and writer
- Mark Williams (music producer), American music producer and songwriter
- Mark Williams (Australian footballer, born 1957), with North Melbourne and Footscray
- Mark Williams (Australian footballer, born 1958), with Port Adelaide, Brisbane, Collingwood, former coach of Port Adelaide
- Mark Williams (Australian footballer, born 1964), with Carlton and Footscray, former coach of Sandringham
- Mark Williams (Australian footballer, born 1983), with Hawthorn and Essendon
- Mark Williams (American football) (born 1971), American football player
- Mark Williams (South African footballer) (born 1966), South African former international footballer
- Mark Williams (footballer, born 1970), Northern Ireland former international footballer
- Mark Williams (footballer, born 1978), English footballer for Rochdale and Rotherham United
- Mark Williams (footballer, born 1981), English footballer who played as a midfielder
- Mark Williams (Scottish footballer) (born 1995), Scottish footballer