The playground was filled with stalls and the field full of games at Nook Lane Junior School which has educated youngsters in the Stannington area since 1972.
Hundreds of current and former pupils and staff along with parents and carers, grandparents, families and friends gathered on the school field in sunny weather to enjoy the festival.
Stannington Training Band opened the proceedings and several other local bands, including present and ex-pupils and staff, performed throughout the afternoon.
Parents provided the stage, sound system and birthday cake, which was baked in the shape of the school logo.
There was a wide range of fun activities for all ages, including some tricky circus skills.
Pupils baked their own cakes and ran stalls, designed cards and wrote poetry dedicated to the school which were displayed alongside photos and recollections of pupils and ex-pupils from their time at Nook Lane.
Nook Lane Headteacher Steven Arbon-Davis said: “We wanted to commemorate our 50th academic year with something a bit special.
“Our amazing PTA, Friends of Nook Lane, took on the challenge, pulling out all the stops to organise a fantastic, truly memorable event for the whole community.
“It was a rip-roaring success; it simply could not have gone any better!
“The last two years have been really difficult for everyone.
“To finally be able to put on a huge event like this and to see Nook Lane’s extended family back together again having such a great time, was indeed very special,” he added.
“We are all massively grateful to everyone involved but especially for the incredible hard work of Friends of Nook Lane, a small but dedicated team of volunteers – Claire, Helen, Kelly, Lisa, Shelly and Sue, plus various staff, especially Miss Braithwaite and Mrs Parkin, who have put countless hours into meticulously planning a 50th birthday party to remember.”
The day also raised £2,136, which will go into the school fund for projects.
Mr Arbon-Davis also thanked the school’s many local sponsors for their continued support.