Donald Keith Johnstone (21 February 1933 – 11 March 2023) was a British-Canadian educator and theatre director.

[3] He grew up hating school, finding that it blunted his imagination and made him feel self-conscious and shy.

After attending St Luke's College Exeter, he taught at a working-class school in Battersea, London in the early 1950s, before being commissioned to write a play by the Royal Court Theatre in 1956.

[6] He retired as artistic director in 1998, but remained involved with the company and continued to work as an educator until 2018, amid a decline in his health.

[6][5] Johnstone's work with performers comprised a vast collection of training games, exercises and lazzi.