In 2017, Coyne was appointed a Member of the Order of Canada by the Governor General for her contributions to Canadian theatre, film and television as an actor and writer.

Her two best-known plays are Kingfisher Days, an adaptation of her critically acclaimed memoir of the same name, and Alice's Affair.

Coyne also appeared in the Fernando Meirelles adaptation of the Jose Saramago novel, Blindness.

In 2006, she won two Gemini Awards for her work on Slings & Arrows: one for Best Performance by an Actress in a Featured Supporting Role in a Dramatic Series and one for Best Writing in a Dramatic Series (shared with her fellow co-creators, Bob Martin and Mark McKinney).

She wrote the screenplay for the 2017 film The Man Who Invented Christmas starring Dan Stevens and Christopher Plummer.