Ontario High

Ontario High is a 9-12 campus of heavily attended scale in Ontario, California, operated by Chaffey Joint Union High, hosting 1,994 students in grades 9 through 12. Enrollment runs roughly 138% above the state mean of about 838.

Within Chaffey Joint Union High, which oversees 11 schools and 22,040 students, Ontario High is one campus in the system.

On demographics, Ontario High logs that 89% of students identify as Hispanic, making the school strongly Hispanic-majority; the rest breaks down as 3% Asian, 3% Black, 2% White. That is considerably more Hispanic than the county at large, where the share is closer to 55%.

On the income-and-resources front, Staff filings list 91 full-time-equivalent teachers, which works out to roughly 21.9:1 students per teacher. That figure is higher than the state norm's 18.2:1 average. Around 87% of the student body qualifies for free or reduced-price meals, which schools and policymakers use as a rough income-mix signal. Set against San Bernardino County (around 74%), the school's rate is noticeably above typical.

Adjusting for the school's free-and-reduced-lunch share, Ontario High tracks the demographic baseline. The model predicts 27.9% given the school's FRL share; actual proficiency is 41.0%.

In the area at large, San Bernardino County reports that the typical household earns roughly $85,478 per year, about 23% of the adult population holds a bachelor's degree or above, and census figures put the poverty rate at about 11%. In all, San Bernardino County runs 583 public schools (combined enrollment of about 393,648 students), of which Ontario High is one.

Nearest neighbor: Richard Haynes Elementary, around 0.2 miles off. 8 of the 8 nearest public schools sit inside a five-mile radius. Ranking that nearby cluster on reported proficiency puts Ontario High at 2nd of 9; the average score across the group is 36.6%.

Ontario High operates from an urban location.

Trend over the last 7 years. Ontario High's enrollment has shrank 16% since 2018, when it stood at 2,388 (now 1,994). Class-load math has fell: from 23.8:1 in 2018 to 21.9:1 in 2025.

On allk12, members of the Ontario High community share and discuss enrollment questions, classroom assignments, and PTA news. The community welcomes input from current and former families.