Ashby was an antiquary and Church of England clergyman, who was born in London in 1724. He came up to St. John's College, Cambridge in 1740 and was elected a Fellow in 1748. He held numerous roles within St. John's, including steward (1766-1767) and President or Vice-Master from 1767-1775. Thereafter he had little to do with Cambridge, surrendering his fellowship, and holding the College living of Barrow in Suffolk to which was eventually added the rectory of Stansfield, also in Suffolk. He then held Barrow and Stansfield until his death. He corresponded with a wide circle of friends which included Thomas Gray. Ashby died at Barrow in 1808.