Danny Grehan (born November 1965) is a Welsh actor and politician who has served as Member of Rhondda Cynon Taf County Borough Council for Tonyrefail East since May 2017. He has portrayed many characters on Welsh stages and television since the 1980s. He received his education at the Royal Welsh College of Music & Drama.
Grehan has lived in Tonyrefail since the 1980s with his wife and his family, which includes his son the Poet Gwynfor Dafydd. In addition to his work as an actor, he also worked for Leanne Wood in the Rhondda.
Grehan played Tony Morgan in the S4C/BBC soap opera Pobol y Cwm from 1994 to 1996. He is involved in the Welsh Language Society. He is also the Community Engagement Officer for Heledd Fychan.
Grehan has represented Tonyrefail East on Rhondda Cynon Taf County Borough Council since 5 May 2017. He is currently a candidate for Afan Ogwr Rhondda for the 2026 Senedd election.