John Greyson (born March 13, 1960) is a Canadian director, writer, video artist, producer, and political activist, whose work frequently deals with gay themes.
Greyson is also a professor at York University's film school, where he teaches film and video theory, film production, and editing.
He was part of a loosely-affiliated group of filmmakers to emerge in the 1980s from Toronto known as the Toronto New Wave.
Greyson has won accolades and achieved critical success with his films—most notably Zero Patience (1993) and Lilies (1996).
His outspoken persona, activism, and public image have also attracted international press and controversy.