 Leaving the choir school at the age of seventeen, Cellier held a series of posts as an organist, first in Belfast, Ireland, and then at the church of St John of Jerusalem, South Hackney, where he had been christened, and in 1870 St Michael's, Lower Sydenham.After a spell as Sullivan's deputy organist at St Peter's, Cranley Gardens, South Kensington, he moved to St Anne's, Surbiton, where he remained for the rest of his career, in tandem with his theatrical conducting work.Cellier married Clara Short in 1873.