Keswick fields competitive middle school and high school teams across a wide range of sports including football, volleyball, basketball (boys and girls), soccer, baseball, softball, cross country, swimming, and track. The athletic program is led by Athletic Director Coach Karrmayne King, who has been inducted into the FHSAA Hall of Fame — the highest honor in Florida high school athletics. Keswick’s athletic standing in the region is significant enough that the school hosts its own invitational tournaments, including the Keswick Invitational and the Suncoast Classic Basketball Tournament, drawing competing schools from across the area.

Recent highlights include boys volleyball championships, boys varsity soccer district titles, girls basketball district championships, cross country and swim regional finals appearances, and football playoff runs. About 69% of students participate in more than one sport, and the athletic program consistently emphasizes character, Christlikeness, and life skills alongside competitive achievement.