High Schools in Chelsea

Chelsea, Massachusetts has two high schools serving grades 9–12, both at the same address, 299 Everett Avenue: Chelsea High, with 1,649 students, and Chelsea Opportunity Academy, with 132 students. Together they enroll 1,781 high-school students, with Chelsea High making up about 92.6% of that total. Both belong to the Chelsea district, which ranks 321 of 351 in Massachusetts at the 9th percentile with 0 stars.

Chelsea High is the larger, more comprehensive school and the relative standout within the city. Its graduation rate of 78.2% is 8.1 points above the district's 70.1%, and its dropout rate of 15.5% matches the district. Its student-teacher ratio is 13.1, and per-student spending in 2020–21 was $17,676. On MCAS Next Generation tests it is slightly above the district in every reported row, by roughly 0.8 to 1.5 percentage points, yet far below the state: proficiency runs around 11–21% compared with state rates of roughly 38–51%. Its own rank history places it near the bottom of the state, about the 10th–11th percentile with 1 star in each recent year. Scores also slipped from 2024–25 to 2025–26 in ELA (21 to 15.7), math (18.59 to 15.36), and science (19.05 to 13.73).

Chelsea Opportunity Academy looks very different: a 25.0% graduation rate, 45.1 points below the district, and a 29.2% dropout rate, 13.7 points above both Chelsea High and the district. Its student-teacher ratio is 18.7, and 2020–21 spending was $16,464. No test scores, rank history, or stars are reported for it, so its academic proficiency cannot be compared directly; as an opportunity academy, it likely serves students on alternative pathways. Free/reduced-lunch data is not reported for either school, leaving economic context unknown.