Jellicoe was born in Chailey, Sussex. A graduate of Magdalen College Oxford, he was ordained as an Anglican priest and became missioner at the Magdalen Mission at St Mary's Church in Somers Town, London. He was founder of the St Pancras Housing Association (originally the St Pancras House Improvement Society) and several other housing associations in London, Sussex and Cornwall. He toured the country in his small car fundraising and selling loan stock to fund these projects. His father, Thomas Harry Lee Jellicoe, rector of St Peter's Chailey, was a cousin of John Jellicoe, 1st Earl Jellicoe.
Jellicoe died in Uxbridge on 24 August 1935. A blue plaque was unveiled in his honour in Camden in 2014. He is commemorated in the Diocese of London with a memorial day on 24 August.