Colonel Frederick Richard Thomas Trench-Gascoigne DSO JP (4 July 1851 – 2 June 1937) was a British soldier and landowner.

His aunt Elizabeth Oliver Gascoigne was the wife of Frederick Mason Trench, 2nd Baron Ashtown.

He was second-in-command and later commanding officer of the 3rd Battalion Imperial Yeomanry in the Second Boer War in South Africa from 1900 to 1901, and was awarded the Distinguished Service Order in 1900.

[4] In 1892, he married Laura Gwendolen (1859–1949), daughter of Sir Douglas Galton and the former Marianne Nicholson.

[6] Together, they had two children, a son and a daughter:[7] The Gascoignes lived at Lotherton Hall, Aberford, Leeds (which he inherited from his aunt, Lady Ashtown, upon her death in February 1893), and Craignish Castle, Ardfern, Argyllshire.