William Hennessy may refer to:
- Bill Hennessy (Cork hurler) (1882–1954)
- Bill Hennessy (Kilkenny hurler) (born 1968)
- William Hennessy (violinist), Australian classical violinist
- William C. Hennessy, American civil servant and political figure
- William J. Hennessy Jr., American court sketch artist
- William John Hennessy, Irish artist
- William Maunsell Hennessy, Irish official and scholar
Topics referred to by the same termThis disambiguation page lists articles about people with the same name. If an internal link led you here, you may wish to change the link to point directly to the intended article. Category: