Root form: Uilliam
Irish-language surnames
Mac Uilliam, Mhic Uilliam, Nic Uilliam
Male form
- Nominative
- Seán Mac Uilliam
- Genitive
- Sheáin Mhic Uilliam
- Vocative
- a Sheáin Mhic Uilliam
Wife form
- Nominative
- Síle Mhic Uilliam
- Genitive
- Shíle Mhic Uilliam
- Vocative
- a Shíle Mhic Uilliam
Daughter form
- Nominative
- Síle Nic Uilliam
- Genitive
- Shíle Nic Uilliam
- Vocative
- a Shíle Nic Uilliam
English-language surnames
- McWilliam
- Williamson
- Williams