Frederick Clarke Withers (4 February 1828 – 7 January 1901) was a successful English architect in America, especially renowned for his Gothic Revival church designs.
Frederick Clarke Withers was born in Shepton Mallet, Somersetshire. He had a brother, Robert Jewell Withers, who also became an architect. He studied architecture in England for eight years. He came to the United States in 1851/52 at the invitation of the prominent American architect Andrew Jackson Downing. Withers and Downing later became family, as they married sisters: Emily Augusta and Caroline Elizabeth DeWindt, respectively. The sisters were great-grandchildren of President John Adams, and grandnieces of John Quincy Adams. Downing drowned that year, attempting to save his mother, following the explosion of the steamboat Henry Clay. Calvert Vaux, Downing's partner, then took Withers in as a partner, at Newburgh, New York. Vaux included a design for a bookcase credited to Withers among those in his Villas and Cottages (New York, 1857), which records both designs of Downing and Vaux and Vaux and Withers.
At the outset of the American Civil War, Withers volunteered and received a commission as a lieutenant in the 1st New York Volunteer Engineer Regiment. This experience added invaluable engineering experience to his architectural expertise. After war's end, he moved his practice to New York City where he became renowned for his church designs. As an independent architect in New York working largely in the Gothic revival mode, Withers wrote about architecture and designed in the highly colored "Ruskinian Gothic" manner. Withers' only cast-iron building stands at 448 Broome Street, Manhattan.
When A. J. Bicknell published Withers' Church Architecture (1873), it was a sign that Withers' reputation was secured. Among his prestigious commissions was the "William Backhouse Astor, Sr. Memorial Altar and Reredos" (1876–77) at Trinity Church. In the 1880s Withers worked in partnership with Walter Dickson (1835-1903), originally from Albany, New York.