William Coles was born in 1626 in Adderbury, Oxfordshire and educated there at the Boys School. At the age of sixteen, he entered New College at University of Oxford and soon after was made a portionist, commonly called post master, of Merton College by his mother's brother, John French, one of the senior fellows of that house and public registrar of the university. While a student, Coles also became qualified as a public notary so that he could stand in for his uncle as registrar. Coles took his bachelor of arts degree in 1650, then left Oxford for London and lived for several years at Putney where he became a well-known simpler. Upon the king's restoration in 1660, he was made secretary to Dr. Brian Duppa, bishop of Winchester, in whose service he died in 1662.