He was the second son of 20 children of the builder and architect Frederick Darley Senior, and his father served as Lord Mayor of Dublin in 1808–1809.
[1] In 1833–1843, Darley was the Ecclesiastical Commissioners architect for the Church of Ireland Diocese of Dublin.
[2] Frederick Darley junior was a pupil of Francis Johnston.
Darley himself was succeeded by his pupil John McCurdy as architect to Trinity College Dublin.
[3] Darley was a founding member of the Royal Institute of the Architects of Ireland (RIAI) and lived on Lower Fitzwilliam Street, Dublin.