The event, this year held at Louth Meridian Centre, was for schools who had won their local area competitions.
It featured 11 different schools from all parts of the county, including Lincoln, Boston, Spalding, Grantham, Horncastle and host town Louth.
The gala was divided into competitions for children in Years 3 and 4, and Years 5 and 6.
In the Year 3 and 4 category, St Michael’s finished as clear winners with 57 points, fully 16 points clear of nearest challengers Horncastle Primary, with Tower Road, Boston in third with 38 points.
The Louth school again came out on top in the Year 5 and 6 age group with a huge total of 126 points.
It gave them victory by 13 points in what became a two-horse race with runners-up Barrowby racking up 113 points. Parish Church finished third on 81 points.
St Michael’s headteacher Paul Fox said: “We were delighted to qualify for the county finals and are over-the-moon to win both categories.
“Although we are larger than many Lincolnshire schools, we are considerably smaller than many we were competing against.
“Across the school year, we take all our children swimming from Foundation Stage to Year 6 and that, along with our close partnership with Louth Dolphins, clearly helped produce these super results.”