Sir Evan Owen Williams (20 March 1890 – 23 May 1969) was an English engineer and architect, known for being the principal engineer for the original Wembley Stadium, and later Gravelly Hill Interchange (known popularly as Spaghetti Junction) as well as a number of key modernist buildings, including the Express Building in Manchester and the D10 and D6 Buildings at the Boots Factory Site in Nottingham.