Nicholls was born in Cambridge, the son of Charlotte (née Johnson) and Arthur N. Nicholls, a professional photographer. Nicholls was apprenticed to his photographer father on the Isle of Wight and in Huddersfield before setting up as a professional photographer in Johannesburg. During the Second Boer War he worked for the London-based periodical South Africa.
During World War I he worked in government information, devoting his later life primarily to his family. He had five children, including noted character actor Anthony Nicholls (with Florence Holderness). He died of diabetes. His grandchildren include Grammy Award winning classical music producer James Mallinson, actor David Mallinson and actress Phoebe Nicholls and his great-grandchildren are actors Tom Sturridge and Matilda Sturridge.
The bulk of Nicholls' work - some 1268 photographs - is held in The Royal Photographic Society's Collection at the National Media Museum, Bradford.