Frederick Trench may refer to:
Frederick Trench (MP for Galway) (1681–1752), Irish MP for Galway County Frederick Trench (MP for Maryborough), Irish Member of Parliament Frederick Trench, 1st Baron Ashtown (1755–1840), Irish MP for Portarlington and Maryborough Frederick Trench, 2nd Baron Ashtown (1804–1880), his nephew, Irish peer Frederick Trench, 3rd Baron Ashtown (1868–1946), his grandson, Irish peer Frederick Trench (British Army officer) (c. 1777–1859), British soldier and Tory politician