Newtownmountkennedy ETNS opened in its temporary accommodation during the week opposite the Community Centre in the town.
Permanent accommodation is currently being sought by the Department of Education and Skills.
Educate Together was granted patronage of the school after an online Department run survey in late 2018.
Parents and carers in Newtownmountkennedy and Kilcoole were asked for their preferred choice of patron and overwhelmingly voted in favour of an Educate Together school.
Educate Together will run seven new schools; The Kilcoole/Newtownmountkennedy primary school here in Wicklow and six others in Kildare, Dublin, and Cork.
An Forus Pátrúnachta will lead two of the schools, and the others will be under the patronage of various education and training boards.