Hermione Norris was born in February 1967 in Paddington, London, but was brought up in Derbyshire from the age of 4 with her mother after her parents divorced, later moving back to London aged 11. She won a scholarship to the Elmhurst Ballet School in Surrey, and later enrolled at LAMDA.

Her professional career kicked off in a theatre production of A Midsummer's Night Dream in 1989, followed by television in the television film Blood Rights in 1990. The following year saw her appear in The Men's Room, Spatz, and Drop the Dead Donkey. Other appearances included Clarissa, Poirot, Cadfael, See You Friday, Berkeley Square and Heartbeat, not to mention the almost obligatory roles in Casualty and The Bill.

Since the late 1990s, Norris has had a number of notable roles on television, kicking off as Karen Marsden in Cold Feet. This was followed by DCI Carol Jordan in Wire in the Blood, Ros Myers in Spooks, Beatrice Kingdom in Kingdom, Stella Isen in Outcasts, and in Spring 2014 as Matron Grace Carter in The Crimson Field.

She married her husband, writer/producer Simon Wheeler, in 2002 and has two children, a son Wilf and daughter Hero.