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?
17. Through the years
Shane, Caitlin and Anna joining in the fun at the St MacNissi's Primary School teddy bears' picnic for Trocaire, 2013. INLT 13-332-PR Photo: P. Rippon
18. Through the years
Looking spooky at the St MacNissi's Primary School Halloween Parade in 2010 were Bailey, Josh, Jordan and Daniel. LT44-350-PR Photo: Peter Rippon
19. Through the years
Pictured at the presentation of the ICT Mark to St MacNissis's Primary School in 2011 are (front): pupils Eva, Tara, Mark, Leiw, Bailey and Niamh; (back): Principal Mrs Brady; ICT Assistant Advisor to NEELB Pearl Garrett; and teachers Mrs Higgins and Miss Wheeler. INLT 48-347-PR Photo: Peter Rippon
20. Through the years
Narrators at the St MacNissi's Primary School P3 and P4 nativity in 2010. INLT 51-325-PR Photo: Peter Rippon