James A. Garfield High School was founded in 1920 as East High School at its current location. The first graduating class consisted of 282 students who transferred from Broadway High School. In three years, the school's enrollment forced the 12-room building to be scrapped for the Jacobean-style building designed by Floyd Naramore. In 1929, the city commissioned the architect to design an addition for the school as enrollment peaked at 2,300 students.
Garfield High School has long played a key role in its neighborhood, the Central District. As the Central District has changed, so has the school's population. In its early decades, the school was noted for its Jewish, Japanese and Italian populations. After World War II, the neighborhood became predominantly African-American and by 1961, 51 percent of Garfield students were black, compared to only 5.3 percent of the general Seattle school district population.
In the late 1960s and 1970s, Garfield was at the center of the school district's attempts to avoid desegregation busing through various plans, including turning it into a "magnet school". This began the focus on music and science that persist to the present day. The school introduced an APP Program in 1979, and due to the success of this program, an alternative program, IBx, was opened for APP students at Ingraham International High School in North Seattle to help relieve pressure on an overcrowded Garfield.