In 1935, funding was acquired to construct three new wings to double the floor space and reduce the overcrowding due to the increasing number of students.

Improvements were designed by architect Alfred Watts, including a one-story cafeteria with a kitchen and six additional classrooms.

In 1958, a football field was added at the east end of the site and tennis courts were constructed near the corner of Littleton Boulevard and Windermere Street.

Earl C. Morris also designed this addition, with general contracting work completed by Weaver Construction Company.

They were led by 4 × 100 m relay gold medalists Nate Yorks and Shane Cronin, who won individual silver medals, second only to 100m/200m state record holder, Jeremy Dodson.

Littleton High school has a long history of exceptional performing arts in theater, band, and vocal music since its inception in 1907.

In the spring of 2008, the school housed the original play The Cliff's Edge, written, acted, and directed by the students of the senior Theater Company class of 2008, and End Process, written and directed by the 2009 senior Theater Company (auditions were open to anyone).

Many of these performances have been recognized and reviewed by Colorado Backstage,[2] a web theater critic site for professional productions across the state.

In 2012, the theater department produced Legally Blonde: The Musical, which received ten nominations in the Bobby G Awards.

The marching band competes in the 4A bracket under the direction of Don Emmons, and has performed shows such as Locomotion, Midnight in Transylvania, Medusa, The Pirates of Penzance, and Machines.

In 2022, the marching band scored an 80.85 with the show Words of Wisdom, loosely based on Let It Be by The Beatles, and was the first in the Metro Denver area to skip state quarterfinals.