The Larne school held an event on September 30 to recognise the important milestone, with pupils also marking the occasion by burying a time capsule filled with messages in the school garden.
We’ve had a look through the archives and turned up these fab photos of events at the school through the years.
Can you spot any familiar faces?
9. Through the years
Charlotte, Eoin, Lauren and Joel working on the computers at St MacNissi's Primary School, 2010. LT41-305-PR Photo: Peter Rippon
10. Through the years
Monica Wilson, the CEO of Disability Action pictured with Mr Oakes and his P7 class at St MacNissi's Primary School during a talk as part of Employability Fest 2007. LT22-328-PR Photo: Peter Rippon
11. Through the years
Jessica, Shannon, Aoife, Gracie, Maeve and Aimee at the St MacNissi's Primary School Pink Day in 2012. INLT 44-307-PR Photo: P. Rippon
12. Through the years
During the 2010 St MacNissi's Primary School P3 and P4 nativity, Mary and Joseph were played by Sophie and Christy. INLT 51-322-PR Photo: Peter Rippon