The pupils from the school, in Vaagen Road, secured nine gold, four silver and eight bronze medals at the event, which was held at Thundersley’s Runnymede Pool.
And that haul was sufficient to see the islander secure the overall winner’s cup too.
“My congratulations to all those children who took part,” said headteacher Paul Collingwood.
“The children have worked and trained hard during their swimming lessons here at school. “This is a great success for St. Joseph’s Catholic Primary School. Special thanks to Miss Hidveghy for managing the team and their swimming coach Mrs O’Halloran.”