William Niall Morris (born 1965) is an Irish classical singer, stage director and voice coach.
Amongst the opera roles he has performed on stage are Nemorino in L'elisir d'amore, Davey in Jonathan Dove's Siren Song, Ralph Rackstraw in H.M.S.
Morris was a founding member of the Irish singing group "The Celtic Tenors" who won the German Echo Klassik Award for Best Classical Crossover Artists in 2002.
The group and made numerous recordings, notably at Abbey Road studios while signed to EMI Classics.
Morris decided to leave the group in 2006, partly due to creative differences, and since then has worked as company manager for Opera Ireland as well as creating a biographical stage show about the life of opera legend Maria Callas which played for eleven nights at the National Concert Hall, Dublin.