Michael N. Harbour, with the "N" standing for Ninian, was born in Edinburgh. He was one of six children of a veterinarian and grew up in London and St. Albans, Hertfordshire. It was there that he developed an interest in amateur dramatics and met his wife, Lesley, whom he married in 1968. Their daughter, actress and voice-over artist Kate Harbour, was born the following year.

He graduated from the Rose Bruford Drama School in Kent and became a member of the BBC Radio Repertory Company. He also presented the children's educational programme "Finding Out." Widely recognized for his stage work at Stratford East, he was an accomplished singer and performed in musicals including "Zorro" and "Into the Woods," although he was ultimately cut from the film adaptation of "Sweeney Todd." He died of cancer in April 2009 while staying with relatives in Cornwall.