Marcia Johnson was Chair of PGC's Women's Caucus from 2006 - 2010. She has had two OAC Playwright Residencies at Roseneath Theatre and Blyth Festival and also received a Toronto Arts Council grant to develop Jumping Ship, based on the lives of her paternal grandparents. Marcia attended the International Women Playwrights Conference in Mumbai with her play, Say Ginger Ale (adapted from her radio drama), which was subsequently produced at the 2010 SummerWorks Festival. Other plays include Late (Obsidian Theatre Company), Courting Johanna (Blyth Festival), and Binti's Journey (adapted from "The Heaven Shop" by Deborah Ellis for Theatre Direct Canada).
Marcia has participated in playwrights' groups at Obsidian Theatre Company, Theatre Passe Muraille and Canadian Stage Company (Bash). She has taken part in two playwriting master classes with Carole Fréchette (through the Siminovitch Prize in 2005 and Playwrights Workshop Montreal in 2011), and Tapestry New Opera's Composer-Librettist Laboratory (Lib Lab). Marcia's short opera, My Mother's Ring, was nominated for a 2009 Dora Mavor Moore award and she continues to collaborate with its composer, Stephen A. Taylor. Their full length opera, Paradises Lost, adapted from the Usula K. Le Guin novella debuted at University of Illinois (2012) and had a concert performance at Musical Works in Concert at the SummerWorks Festival in Toronto (2013).
Also an actor, Marcia's professional acting debut was in 1983 on the CBC TV series Hangin' In. Other roles include The Real McCoy by fellow actor/playwright Andrew Moodie at Factory Theatre in Toronto and Great Canadian Theatre Company in Ottawa. She was also an original cast member for the 2007 Fringe runaway hit, The Gladstone Variations. In 2014, she appeared in an all-female production of Julius Caesar at the RED Sandcastle Theatre and in Credi by Ryan Hughes at the Lab Cab Festival.
Publications include Binti's Journey (Things that Go Bump, Volume 1: Plays for Young Adults - Signature Editions); Linden’s Sister (More than a Play - Elementary Teachers’ Federation of Ontario), and Late (short version) in Give Voice: Ten Twenty Minute Plays from the Obsidian Theatre Company Playwrights Unit.