Munro married James Munro in 1951. Their daughters Sheila, Catherine, and Jenny were born in 1953, 1955, and 1957 respectively; Catherine died 15 hours after birth.
In 1963, the Munros moved to Victoria where they opened Munro's Books, a popular bookstore still in business. In 1966, their daughter Andrea was born. Alice and James Munro divorced in 1972.
Munro returned to Ontario to become writer in residence at the University of Western Ontario, and in 1976 received an honorary LLD from the institution. In 1976, she married Gerald Fremlin, a cartographer and geographer she met in her university days. The couple moved to a farm outside Clinton, Ontario, and later to a house in Clinton, where Fremlin died on 17 April 2013, aged 88. Munro and Fremlin also owned a home in Comox, British Columbia.
At a Toronto appearance in October 2009, Munro indicated that she had received treatment for cancer and for a heart condition requiring coronary-artery bypass surgery.
In 2002, her daughter Sheila Munro published a childhood memoir, Lives of Mothers and Daughters: Growing Up With Alice Munro.