Sports were first introduced at Laconia High School in 1923, following the move to the Union Avenue campus. The 6-acre (24,000 m²) campus and new building, which included a gymnasium, allowed the school to offer football, basketball, and baseball for male students during the fall, winter, and spring seasons, respectively. Later in the 1920s,
field hockey was the first sport to be offered to girls. Currently, there are five varsity sports offered for men, six varsity sports offered for women, and eight coed varsity sports at LHS. As of the 2018-19 school year, Laconia is classified as a Division II program in the
New Hampshire Interscholastic Athletic Association, however, in some sports, they petition down and compete in Division III due to low participation. The following sports are offered: Laconia has historically been strong at football, winning 10 championships and appearing in the finals 20 times in the last six decades. The Sachems Football team won the NH Division IV finals against
Hanover in the fall of 2007, 35-14, to complete their undefeated 11-0 season and their first championship since 1999. Since the fall of 2018, the team plays in division III of the NHIAA. ==Notable alumni==