Mark Johnston

Mark Johnston may refer to:


 * Mark Johnston (racehorse trainer) (born 1959), Scottish racehorse trainer
 * Mark Johnston (historian) (born 1960), Australian historian, teacher and author
 * Mark Johnston (American football) (born 1938), American football cornerback
 * Mark Johnston (swimmer) (born 1979), freestyle swimmer from Canada
 * Mark Johnston (philosopher), Australian philosopher
 * Mark T. Johnston (born 1970), jockey in thoroughbred horse racing
 * J. Mark Johnston, member of the South Dakota Senate