[5][6] The school was founded in 1956 and named after Walter Johnson, a famous baseball player who was also a native of Montgomery County, Maryland.

The school first opened to grades 10-12 in 1956,[8] and was named after the baseball pitcher and politician, Walter Johnson who lived in the area and had died 10 years prior.

[14] This APEX-Reach Program leads students through a more rigorous curriculum through a combination of honors and Advance Placement (AP) classes.

[14] Since the fall of 2023, Montgomery County Public Schools (MCPS) will pay for all AP and International Baccalaureate (IB) exams that students who take these courses will take.

In the merge with the Charles W. Woodward High School, more lockers, trophy cases, and seven portable classrooms were added.

[8] The construction took ten years which include new installations like 19 more classrooms, 4 more science labs, a new cafeteria, stadium, media center, new gym, and new auditorium.

In the fall, the school offers cross country, field hockey, football, golf, pom's, soccer, and volleyball.

[23] Walter Johnson has classes to support their literature with their own newspaper, The Pitch, as well as their own literary magazine, The Spectator.