Around 800 pupils from Carr Manor High School in Meanwood made hats out of white paper and wore them for 10 minutes - setting the new world record for the Most people wearing papr hats in one place.
The Guinness world record for the largest knitted hat measures 6.90 metres (22 ft 7 in) in height and 15.05 metres (49 ft 4 in) in circumference and was created by volunteers from all over Europe.
Guinness World Records also recognized the world record for the largest hat mosaic consisted of 1,861 caps which was achieved by New Era Cap Company Ltd (Global), at Bread and Butter tradeshow, in Berlin, Germany.
The school was aiming to break the previous Guinness World Record for the number of people wearing paper hats, which was set at just over 400 before Christmas - and with around 800 taking part, they smashed it.
Each hat was made during the school's coaching sessions and contained some of the pupils hopes and dreams for 2012, with messages ranging from "get 13 GCSEs" and "get better at English" to "run a marathon personal best" and "I want to be heard".
Sarah Holdsworth, the school's assistant head in charge of personal development and wellbeing, said: "We decided a while ago that we wanted to break one of the existing Guinness world records. Hats was something which was feasible so we decided to go for it, and it's linked to the pupils setting their own individual targets for the forthcoming year.
"I think the pupils had a fantastic time in breaking the Guinness world record - 10 minutes is quite a long time but I think they really enjoyed it."