John Chamber (May 1546 – August 1604) was a fellow of Merton College, Oxford, and later of Eton College, a clergyman of the Church of England and an author, especially on astronomy and astrology. He taught grammar, Greek, and medicine. His name is sometimes given in a Latin form as Johannes Chamberus.
Apart from his baptism at Swillington in Yorkshire in May 1546, nothing is known about Chamber's family or his life before Oxford. In October 1568 he graduated BA at Merton College, Oxford, and in December of the next year was elected a probationary fellow of his college. He proceeded to MA in October 1573, having already taken holy orders. In 1574 he was appointed a lecturer on grammar and gave an oration on Ptolemy's Almagest. In 1576 he was appointed a lecturer on Greek and was also chosen as junior Linacre lecturer in medicine, a Merton College appointment which was repeated in 1579. In 1582 his life changed direction dramatically when he was elected to a fellowship at Eton and moved to Windsor, giving up his fellowship at Oxford. In 1583, Burghley appointed Chamber, with Henry Savile and Thomas Digges, to sit on a commission to consider whether England should adopt the Gregorian calendar, as proposed by John Dee, and in 1584 he applied through Merton for a licence to practise medicine.