A free-spirited individual who has worked as screenwriter, producer and script editor for both his brother, Gillies MacKinnon, and Jane Campion, Billy MacKinnon came into his own with the 1995 release of "Small Faces", which he produced and co-wrote with his brother. The poignant yet hearty coming of age tale of a 14-year old lad in the low-income housing projects of Glasgow in 1968, "Small Faces" won near unanimous praise and has been acknowledged as semi-autobiographical. MacKinnon and his brother had previously worked together on "Passing Glory" (1986), which served as Gillies' graduation thesis from the Glasgow School of Art.
While his older brother has gone on to make numerous other films, MacKinnon has chosen to travel throughout the world, living in Morocco, London and Sydney, Australia. While Down Under, he met and became romantically involved with New Zealand-born filmmaker Jane Campion. Billed as William MacKinnon, he served as producer and script editor on her debut feature "Sweetie" (1989). He also worked as script editor on her Oscar-winning screenplay for "The Piano" (1993), but by the time of its release, their personal relationship had ended. Additionally, he has produced two nonfiction films, Sue Clayton's "The Last Crop" and "Motherland". MacKinnon has long been developing the Christopher Isherwood memoir "My Guru and His Disciple" as a feature film.