Born in Toronto in 1973, Pettle is a graduate of the National Theatre School of Canada's (NTS) playwriting program.
[1] His first play, Therac 25 (1995), is autobiographical – Pettle received extensive treatment for thyroid cancer in the early 1990s.
[1] In 2006, Pettle began his move towards television writing, penning an original pilot Clean for Ilana Frank and Thump Inc (now ICF Films).
[4] He has since worked on several Canadian and American television series, including Combat Hospital, King, Rookie Blue, X Company, and Saving Hope.
[5] He was nominated a Gemini Award in 2010 for a Rookie Blue episode entitled "Big Nickel," co-written with Morwyn Brebner.