Sir Walter fitz Gilbert of Cadzow, 1st Laird (Lord) of Cadzow (died ca. 1346) was a Scottish nobleman. The husband to Mary Gordon of Huntly, they wed in 1308 in Cadzcow, Lanarkshire, Scotland (the exact date is unknown). He is the first historically confirmed progenitor of the House of Hamilton, which includes the Dukes of Hamilton, Dukes of Abercorn and Earls of Haddington.