John Thornton Masser (24 June 1855 - 23 February 1929) was an organist and composer based in Nottingham.
He was educated at Bradford High School, Fulneck Moravian Settlement and Bramham College, Tadcaster.
On 11 July 1885 he married Jessie Margaret, the youngest daughter of Henry Legge of Holly Park, Crouch Hill, Middlesex.
From age 17 to 22 he worked in the family business, but then was articled to Thomas Bradley Chambers of Brighouse, senior partner in a Yorkshire firm of solicitors.
He also compiled and published a psalter and tune book, both of which were in constant use at Addison Street Congregational Church in Nottingham, where he was Hon.