His father was named William as well but you will have to go to his birth record in Tasmania to access his mother's name.
Digger - South Australian Marriages, Registrations 1842-1916
Query ----- Groom:sullivan (107 matches) Given names:william (20673 matches) Total matching records: 8 --------------------
Groom: SULLIVAN Given names: William Bride: HODGE Given names: Mary Date: 1867-11-25 Groom Age: 24 Status: N Groom's Father: William SULLIVAN Bride Age: 19 Status: N Bride's Father: William HODGE Place: Wesleyan Parsonage Pirie St Adelaide District: Ade Symbol: Book/Page: 73/331 Cross Reference:
Groom: SULLIVAN Given names: William Bride: WOODINGS Given names: Harriet Date: 1872-12-07 Groom Age: FL Status: S Groom's Father: William SULLIVAN Bride Age: 20 Status: S Bride's Father: John WOODINGS Place: St Michael Church Mitcham District: Ade Symbol: A Book/Page: 93/546 Cross Reference: