Fiach
Fiach is an Irish male given name. It may refer to:
- Saint Fiacc, fifth-century bishop of Sletty in Ireland
 - Fiach McHugh O'Byrne (1534–1597) Irish chief
 - Fiach Mac Conghail (born 1964) Irish theatre director and Senator
 - Fiach Moriarty, Irish singer-songwriter
 
See also
- Tomás Ó Fiaich, Irish Catholic primate and cardinal