Roger Flexman (1708–1795) was an English Non-Subscribing Presbyterian (Unitarian) minister, known also as a chronological and historical scholar, and published as an indexer and bibliographer.
He showed early promise, and at the age of fifteen (1723) was admitted to the academy of John Moore, presbyterian minister at Tiverton, Devon, to study for the ministry.
He declined an offer from Moore of the post of tutor in the academy, and applied to the Exeter assembly on 7 May 1728 to admit him to examination for license.
In 1754 he was chosen one of the preachers of the Friday morning lecture, founded in 1726 at Little St. Helen's, Bishopsgate, by William Coward (died 1738).
Heterodox in theology, Flexman was conservative in his religious philosophy, and in later life opposed materialists and necessarians.
His reputation introduced him to some of the leading politicians of his day, and, having already shown skill as an index-maker, he was appointed (1770) one of the compilers of the general index to the journals of the House of Commons of Great Britain.
In Psalms and Hymns for Divine Worship, 1760, edited by Michael Pope, presbyterian minister of Leather Lane, are four compositions, signed ‘F.,’ and contributed by Flexman.