William, Willie, Will, Billy or Bill Griffin may refer to:
Arts and entertainment William Griffin (painter) (1811–1870), New Zealand painter Billy Griffin (born 1950), American singer-songwriter Rakim (William Michael Griffin Jr., born 1968), American rapper Bill Griffin (musician), American mandolinist and luthier
Religion William Richard Griffin (1882–1944), American Roman Catholic bishop William A. Griffin (Roman Catholic bishop) (1885–1950), American Roman Catholic Bishop of Trenton William A. Griffin (Christian churches and churches of Christ) (fl. 1980s–2000s), Christian preacher and President of Mid-Atlantic Christian University
Sports Willie Griffin (1922–1983), Irish hurler Billy Griffin (footballer) (born 1940), English footballer, see List of Sheffield Wednesday F.C. players William Griffin (rugby) (fl. 1950s), Welsh rugby union and rugby league footballer
Others William Henry Griffin (1812–1900), Canadian civil servant William D. Griffin (1936–2011), American historian, author, and educator William Griffin (geologist), recipient of the Clarke Medal for 2013 in the field of geology
See also Griffin (surname)