William Rennie

William Rennie may refer to:
 * William Rennie (Victoria Cross) (1822–1887), Scottish recipient of the Victoria Cross
 * William Rennie (horticulturist) (1835–1910), scientific farmer and seed merchant in Ontario
 * Willie Rennie (William Cowan Rennie, born 1967), Scottish politician
 * William J. Rennie (1891–1964), American football and basketball coach
 * William Hepburn Rennie, British colonial official in Hong Kong and St. Vincent