William O'Sullivan

William O'Sullivan may refer to:

• William S. O'Sullivan (1928–1971), Irish-American loanshark and mob enforcer
• William O'Sullivan (politician), Irish Cumann na nGaedheal politician
• William Henry O'Sullivan (1829–1887), Irish Home Rule League politician
• Billy O'Sullivan (footballer) (born 1959), English former footballer

See also

• Billy O'Sullivan (disambiguation)
• William Sullivan (disambiguation)