The College has an affiliated primary school: St. Paul's Co-educational College Primary School, once divided into two half-day schools: St. Paul's Co-educational (Kennedy Road) Primary School and St. Paul's Co-educational (Macdonnell Road) Primary School to cope with the demand for places, they resumed full-day education in 1999.
While the College is an English as a Medium of Instruction (EMI) school, most of the primary school curriculum is taught in Cantonese, with some lessons taught by native English teachers.