Purchas was born at Thaxted, Essex, and graduated at St John's College, Cambridge, in 1600; later he became B.D., and was admitted at Oxford in 1615. In 1604 he was presented by James I to the vicarage of Eastwood, Essex, and in 1614 became chaplain to Archbishop George Abbot and rector of St Martin's, Ludgate, London. He had previously spent much time in London on his geographical work. In 1613 he published the first volume of his Pilgrimes series. The last of these, Hakluytus Posthumus is a continuation of Hakluyt's Principal Navigations and was partly based on manuscripts left by Hakluyt.
The fourth edition of the Pilgrimage is usually catalogued as vol. v. of the Pilgrimes, but the two works are essentially distinct. Purchas died in September or October 1626, according to some in a debtors' prison. None of his works was reprinted till the Glasgow reissue of the Pilgrimes in 1905-1907. As an editor and compiler Purchas was often injudicious, careless and even unfaithful; but his collections contain much of value, and are frequently the only sources of information upon important questions affecting the history of exploration.