Pomeroy was born in London, the son of an artist-craftsman. After his father died in 1869 Pomeroy, aged 14, was left as the main wage-earner for the family and was apprenticed to a firm of architectural stone carvers. Later he trained, for four years, with William Silver Frith at the South London Technical School of Art where he was also taught by Jules Dalou. The naturalistic style of Dalou's sculptures were a great influence on Pomeroy's subsequent works. In 1880, Pomeroy was able to enrol in the Royal Academy Schools, where he won a number of prizes, including silver medals in both 1882 and 1883. In 1885 he won a gold medal and travelling scholarship which allowed him to study in Paris under Antonin Mercié and also in Italy.