Londonderry High School (LHS) is a public secondary school serving grades 9 through 12 in the town of Londonderry, New Hampshire, United States. It is the sole secondary school in the Londonderry School District. It was constructed in 1972 as a junior high school and adopted its current role in 1982. The school is known for its large touring marching band. Its athletics teams compete as the Lancers.