Molly was born Mary Weir, on 17 March 1910, in Springburn, Glasgow, the sister of broadcaster and naturalist Tom Weir (b.1914). She was brought up by her mother and grandmother after her father was killed during World War I. She began as a typist in a solicitor's office in Glasgow and was capable of 300 words-per-minute shorthand, becoming a British champion.
After experience in amateur dramatics, she landed the role of Ivy inThe McFlannels and turned professional. In 1940 she moved to London and joined the cast of Tommy Handley's It's that man again. In 1950 she was offered the part that brought her national fame, Aggie the housekeeper in Life With The Lyons.
She contributed regularly to Woman's Hour and was a writer and performer on Children's Hour. Her television appearances included children's programmes Rentaghost and Flowers of the Forest. Film roles included roles in The Prime of Miss Jean Brodie, Carry on Regardless, Hands of the Ripper and One of our Dinosaurs is Missing.
Molly Weir died on the 28 November, 2004.