William Weir

William Weir may refer to:


 * William Alexander Weir (1858–1929), Quebec lawyer and politician
 * William Weir (architect) (1865–1950), Scottish restorer of historic buildings
 * William Weir, 1st Viscount Weir (1877–1959), Scottish industrialist
 * William Weir, 3rd Viscount Weir (born 1933), British peer and businessman
 * William Gilbert Weir (1896–1971), Canadian politician
 * Bill Weir (born 1967), co-anchor of Good Morning America Weekend Edition
 * Bill Weir (footballer), Australian rules footballer
 * William Weir (aviator) (1891–?), World War I flying ace
 * William Weir (trade unionist) (1868–?), British coal miner and politician