Students at Cowley and Spalding Academy helped raise over £4,000 for Comic Relief.
A special non-uniform day for pupils saw them invited to wear something red in return for a donation to the charity.
The South Lincolnshire Academies Trust, which oversees both schools, Bourne and St Giles Academy in Old Leake, Boston, raised a total of £4,131.
A trust spokesman said: “Thank you very much to all the students and staff who generously donated their money to Comic Relief / Red Nose Day for our non-uniform day.
“This money will towards the £34 million that Comic Relief has already raised this year to help support incredible projects and organisations that are making a real difference for people across the UK and around the world – this includes helping people who are experiencing homelessness, mental health problems and food poverty.”