Irish and English.
Maureen is an Anglicized form of Máirin, as are Moira/Moyra. Máirin is a pet name for the Irish Gaelic name Máire (a variant of Maria/Mary [q.v.]).
NB Maureen is not a spelling variant of Moreen. This is the Anglicized form of the Gaelic Móirin a pet name for Mór.