Grammar school

The school, also referred to as SJN, was formed as a grammar school in 1669 by Sir John Nelthorpe, who was born in Brigg in 1614. He was unmarried and wanted his wealth from his estate across Lincolnshire to create a school in his name. The buildings were opened around 1680, and the Upper School Library dates from this time. New buildings were added in 1879, and the Nelthorpe family have retained strong links with the school.

The grammar school in the 1970s had around 350 boys. Brigg Girls' High School, on Wrawby Road, had around 250 girls, and became the lower school. These schools were administered until 1974 by the Lindsey Education Committee, based in Lincoln.

Comprehensive

The school became a co-educational comprehensive in 1976.

Building improvements have included a new canteen, refurbishment of the drama hall and science labs, redecoration of English classrooms and improved security. The school was one of two in Humberside LEA that had a boarding house; Bridlington School (a former grammar school) was the other. Since 1996 it has been administered by North Lincolnshire; the LEA's offices are also in Brigg.^{[citation needed]}

Brigg Grammar School

• William Eric Grasar (1924–31), Roman Catholic Bishop of Shrewsbury 1962-80
• Robert Hudson (1934–41), Professor of Organic Chemistry from 1967–85 at the University of Kent
• Eric Waldram Kemp (1926–33), Bishop of Chichester 1974-2001
• Kenneth Jones (1932-9), High Court Judge (died 2004), who prosecuted the Kray Twins
• John Pimlott (1959–66), military historian
• Alexander Trees, Baron Trees, Professor of veterinary parasitology and Crossbench member of the House of Lords

Sir John Nelthorpe School

• Duncan Heath, first-class cricketer
• John Heath, first-class cricketer
• John Osbourne, writer and broadcaster
• Matt Sparrow, footballer
• David Yelland, former editor of The Sun from 1998–2003, from 1976 to 1981.
• Holly Mumby-Croft, British Conservative Party politician, serving as the Member of Parliament (MP) for Scunthorpe (2019-)

Brigg Girls' High School

• Sylvia Jackson (1958–65), Labour MSP for Stirling from 1999-2007
• Carmel McCourt, singer