Students and teachers from Blatchington Mill School presented a “Send My Sister to School” petition to 10 Downing Street.
They were joined by Mike Weatherley, the Conservative MP for Hove, who helped organise the trip.
The Send My Sister to School campaign focuses on giving girls the same chance as boys to benefit from education.
Around the world 67 million children miss out on school because of poverty.
Nearly 5,000 schools across Britain are taking part in the campaign and pupils from Blatchington Mill School have written messages of support to be delivered to the Prime Minister.
Mr Weatherley accompanied two teachers and three pupils as they handed in the petition which included hundreds of messages of support.
Mr Weatherley said: “It’s great to be able to support such a good cause.
“The students from Blatchington Mill have run an excellent campaign and I was delighted that I could help by arranging the trip to Downing Street.
“The lack of education for a huge number of children around the world, particularly girls, is worrying and I hope that the Send My Sister to School campaign will help raise awareness.”
