Samuel Medley (1738–1799) was an English Baptist minister and hymn-writer.
He was the second son of Guy Medley (died 25 October 1760), born at Cheshunt, Hertfordshire, on 23 June 1738; his father kept a school there, married the youngest daughter of William Tonge, schoolmaster at Enfield, and was a close friend of James Hervey. He was educated by Tonge, his maternal grandfather, and at 14 was apprenticed to an oilman in the city of London. In 1755, however, he obtained his freedom on entering the Royal Navy, from which he was discharged after being wounded in the Battle of Lagos on 18 August 1759.
From 1762 to 1766 Medley kept a successful school in King Street, Soho, London, and became acquainted with Andrew Gifford. He joined Gifford's Particular Baptist church in Eagle Street, Holborn, in December 1760, and Gifford then led him to enter the Baptist ministry. He began preaching on 29 August 1766, and on 6 June 1767 he accepted a call to a congregation at Watford, Hertfordshire, which had been without a minister since 1763. Here he was ordained on 13 July 1768. On 11 November 1771 he was invited to the Baptist church in Byrom Street, Liverpool, and began his ministry there on 15 April 1772.
Medley's Liverpool meeting-house was enlarged in 1773, and in 1789 a new building was erected for him in the same street. His old meeting-house was consecrated in 1792 as St. Stephen's Church. Medley worked among the seamen of the port of Liverpool; his methods of preaching were disliked by Gilbert Wakefield; but his daughter collected up some of his witticisms, and Robert Halley ranked him as a great preacher. Adult baptism was not an essential for membership in his church, which became practically Congregational.
Medley visited London yearly, preaching at the Surrey Chapel and Whitefield's Tabernacle, Tottenham Court Road. After a painful illness he died on 17 July 1799.