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About Us

The Chaffey Joint Union High School District serves the communities of Ontario, Montclair, Rancho Cucamonga, and portions of Fontana, Upland, Chino, and Mount Baldy. With over 25,000 students, the District is the fourth largest high school district in California. It has eight comprehensive high schools, a continuation high school, an online high school, a community day school, an adult school, and alternative programs. The District offers a wide variety of instructional options that provide a quality education for each student, every day. The District's well-prepared, dedicated, and highly qualified teachers and support personnel are second to none.
 
The Chaffey Joint Union High School District Board of Trustees are steadfast in the belief that "Nothing is more important than student learning and their achievement."
 
Our daily purpose encompasses our commitment:
"To provide student learning, and ultimately their achievement, of the prescribed curriculum that takes place in the classroom under the direction of the teacher." The Chaffey District supports this daily act. We realize that our efforts uniquely influence the future of our community and of this nation, and we are passionate about doing whatever it takes to prepare students to be successful and contributing citizens of the 21st century.
 
The Chaffey District has provided a quality education for high school students in the area since 1911. As the District continues to grow and progress, we are poised to meet the challenge of providing the finest quality education possible for every student. 
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All CJUHSD students will graduate ready for college and careers.

Recent News

Upcoming Events

Board Meeting

Time: 12 PM – 2 PM
Location: Los Osos High School

School Facts

  • 56% of Ontario High School graduates meet the University of California and California State University A-G admissions requirements, making it a leader in San Bernardino County.
  • 85% of freshmen at Ontario High School complete their first year of high school on track to graduate.
  • The CJUHSD has been named a Top Workplace by the Press-Enterprise and Inland News Group.
  • 522 Advanced Placement exams are administered to students at Ontario High School annually.

Principal's Message

Portrait of Larry Rook
Dear Jaguar Families,
 
As we approach the close of the 2025–2026 school year, I want to take a moment to express how proud I am of the achievements, resilience, and growth shown by our students. It has truly been a year to remember.
 
The final day of school for students in grades 9–11 will be Thursday, May 21, 2026. For our graduating seniors, we look forward to celebrating your accomplishments at our Commencement Ceremony on Wednesday, May 20, 2026 at 6:30 p.m. We are incredibly proud of the Class of 2026 and all they have achieved.
 
With just a few short weeks remaining, it is essential that students stay focused and finish the semester strong. We encourage all families to continue monitoring academic progress through Canvas and maintain communication with teachers and counselors regarding any questions or concerns.
 
Summer School will run from May 27 through June 28, 2026. We encourage students to take advantage of the academic opportunities available during this time. For questions about enrollment or course offerings, please contact your student’s counselor.
 
Final Exams for students in grades 9–11 will take place Tuesday, May 19 through Thursday, May 21, 2026, and these will be minimum days. Students should prepare by reviewing class materials and seeking support as needed.
 
The schedule is as follows:
 
Tuesday, May 19                 Wednesday, May 20            Thursday, May 21
Period 6: 8:30–10:30           Period 5: 8:30–10:30           Period 4: 8:30–10:30
Period 3: 10:50–12:50         Period 2: 10:50–12:50         Period 1: 10:50–12:50 
 
(There will be no school on Friday following finals.)
 
Congratulations to the Class of 2026! Your hard work, leadership, and determination have made a lasting impact on Ontario High School. We look forward to celebrating you and all that lies ahead.
 
With Jaguar Pride,
 
Mr. Rook
Proud Principal, Ontario High School