Joanna Marie Shimkus (born 30 October 1943) is a Canadian film actress. She is the widow of actor Sidney Poitier and mother of actress Sydney Tamiia Poitier.

Joanna Marie Shimkus was born in Halifax, Nova Scotia, to Joseph Shimkus, a Jewish father of Lithuanian descent, and Marie Petrie, a Roman Catholic of Irish descent. Her father worked for the Royal Canadian Navy. She attended a convent school and was brought up in Montreal.