Bill, Billy, Willie, or William Paul may refer to:
Politicians
- William Paul (MP), British MP for Windsor, 1710–1711
- William Paul (attorney) (1885–1977), Alaskan politician and attorney
- William Paul (Australian politician) (1846–1947), New South Wales politician
- William Paul (British politician) (1884–1958), also known as Bill, socialist politician
- William Paul (New Zealand politician) (1875–1942), New Zealand politician
- William James Paul (1854–1929), Canadian politician
- William Sheffield Paul, Member of the Queensland Legislative Assembly, Australia
Sports
- William Paul (footballer, born 1869) (1869–1911), Scottish footballer
- William Paul (footballer, born 1868) (1868–1932), Scottish footballer
- Bill Paul (cyclist) (1910–2003), cyclist and tandem rider
- William Paul (judoka), American who participated in Judo at the 1967 Pan American Games
- Willie Paul (bowls) (born 1944), Scottish international lawn bowler
Musicians
- Billy Paul (1934–2016), American soul singer
- Billy Paul (fl. 1970s), saxophonist with Wizzo Band
Others
- Rev William Paul (1754-1802) Chaplain in Ordinary in Scotland to King George III of the United Kingdom
- William Paul (author) (born 1955), Scottish editor and author
- William Paul (died 1773), older brother of John Paul Jones
- William Paul (bishop) (1599–1665), Bishop of Oxford and Dean of Lichfield
- William E. Paul (1936–2015), American immunologist
- William Paul (horticulturalist) (1822–1905), British horticulturalist, Victoria Medal of Honour
- William Paul (Utah architect) (1803–1889), architect in Utah
- Bill Paul (computer science), software developer associated with the FreeBSD project, see NDISwrapper
- William Wayne Paul (1939–1989), American martial artist, educator and social/political activist