Phillips was born in London. Following some political difficulties in Leicester where he was a schoolteacher and bookseller, he returned to London, established premises in Paternoster Row, St. Paul's Churchyard, and founded 'The Monthly Magazine' in 1796. He built up a prominent fortune based on the speculative commission of newly revised textbooks and their publication. His 'Juvenile Library' published in 1800–03 provided the steady returns of all successful children's books. By 1807 he was in sufficient standing to serve as a Sheriff of London, at which time he was knighted on the occasion of presenting an address. He was a successful author both under his own name and at least five pseudonyms. Phillips overextended himself and was declared bankrupt in the Bank Panic. He died in Brighton and is buried in the western extension of St Nicholas' Churchyard. He was a prominent proponent of vegetarianism.