Mary Cunningham appeared on Coronation Street in three roles:
- Mrs Harper in April 1983
- Jean Casey, mother of garage mechanic Mark Casey, in June 1989 and October 1990
- Sandra Hesketh, daughter of the late Sidney Templeton between August and September 1999.
Other credits include roles in Horace, The Practice, Brookside, Children's Ward, The Case-Book of Sherlock Holmes, Touching Evil, Casualty, Hollyoaks, Outlaws, Goldplated, Wire in the Blood and The Royal Today, along with the TV movies My Beautiful Son, Flesh and Blood, The Booze Cruise, Indian Dream, Reversals and the 2003 feature film Wondrous Oblivion.
On stage she has appeared in productions of A Touch of the Red Noses, Old Mother Hubbard, Spring and Port Wine, The House of Bernarda Alba and The Dirty Hill.