ETHS was established in 1883 and serves the city of Evanston and a small portion of the neighboring village of Skokie for a total district population of approximately 78,000.

In 1875, Evanston's first Board of Education voted to establish a "high school" in the room, and the first class, consisting of two students, graduated in 1876.

Enrollments grew rapidly and, despite multiple relocations to various buildings, by 1882 the school took four prizes in a statewide competition and was ranked third best in Illinois.

[8] Enrollment grew rapidly and by 1913, despite multiple additions to the original building, 740 students occupied space meant for only 600.

Finally, in 1921, the Board and voters approved a 55-acre (220,000 m2) site at the school's current campus, 1600 Dodge Avenue in central Evanston.

[9] With a campus currently listed as 65 acres (263,000 m²), ETHS provides its students with many technically proficient facilities.

Computer software is available for many courses in the curriculum and the STC is open to students and classes during all school hours.

Classes include Child Development, Business Management, Culinary Arts, where students work hands on with food, and learn how to prepare it in a safe and sanitary way, and Auto-Tech, where students run an auto-repair lab and learn engineering applications in computer-aided design, lasers and robotics using state-of-the-art equipment.

Performance facilities include a 1,400-seat auditorium, two additional theaters, and a cable TV broadcasting studio.

[12] There are 12 gyms including a dance studio and fitness/wellness center, two swimming pools, and a field-house with an indoor track and tennis courts.

[13] In 2023, the school received media attention after it began offering AP math classes which were "restricted to students who identify as Latinx" or Black.

[20] Evanston Township High School's Willie the Wildkit mascot appears to have originated during the 1946-47 academic year.

ETHS is a member of the Central Suburban League, and participates in state championship tournaments sponsored by the Illinois High School Association (IHSA).

[25] The following competitive teams have won their respective IHSA Sponsored state championships: Students compete in contests in math, science, forensics, world languages, speech, writing, and many other subjects.

Student-led publications include the Evanstonian newspaper, the Paper Clip, and the award-winning school yearbook, The Key.

[34] YAMO is an annual musical sketch comedy show created entirely by students, since 1957, in the school's Upstairs Theatre.