The Mayor of Wigan Coun Sue Greensmith joined the celebrations to mark the end of refurbishment work at Shevington Vale Primary School.
She cut the ribbon to officially reopen the school, which has been modernised and now has extra classrooms.
The work was carried out as 40 extra pupils joined the school after the closure of Shevington Community Primary School.
A special event was held on Wednesday, which saw musical performances by pupils, visits by invited guests and discos for the children.
Executive headteacher Karen Tomlinson thanked everyone involved with the school for their support.