Milne was born in Cambuskenneth, near Stirling.
Milne was one of the artists shown in the 1978 show The Artists of Craigmill and Cambuskenneth at the Smith Art Gallery.
Exhibited at the Royal Glasgow Institute of the Fine Arts and the RSA.
His work is represented in many public art galleries (see http://www.bbc.co.uk/arts/yourpaintings/artists/william-watt-milne" class="link1">BBC Your Paintings) and the European Art Gallery in Dallas, Texas in the USA.