Fulk I FitzWarin ( born 1115, died 1170/1) (alias Fulke, Fouke, FitzWaryn, FitzWarren, Fitz Warine, etc., Latinised to Fulco Filius Warini, "Fulk son of Warin") was a powerful marcher lord seated at Whittington Castle in Shropshire in England on the border with Wales, and also at Alveston in Gloucestershire. His grandson was Fulk III FitzWarin (c. 1160–1258) the subject of the famous mediaeval legend or "ancestral romance" entitled Fouke le Fitz Waryn, himself the grandfather of Fulk V FitzWarin, 1st Baron FitzWarin (1251-1315).