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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

Drive for Excellence - New Car Giveaway!

This school year seniors from Ontario HS, Colony HS, Etiwanda HS, & Alta Loma HS will be eligible to participate in the Drive for Excellence New Car Giveaway.
WeTip - Be the solution


Be the Solution. If you have information regarding crime or misconduct at your school, call WeTip anonymously.

The Chaffey District Cares

The Chaffey District cares about your mental well-being. We partner with community agencies and mental health professionals to provide support to our students and staff. If you, or someone you know, is in crisis please contact the Community Crisis Response Team (909) 421-9233 - Click 'Read Full Story' for more information.

Upcoming Events

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.
  • 90% 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.
  • 500 Advanced Placement exams are administered to students at Ontario High School annually.

Principal's Message

Mr. Rook
Dear Jaguar Family,
Welcome back to Ontario High School for the 2022-2023 school year.  We hope you are having an enjoyable summer! It was a pleasure having students back on campus for in-person learning for a full two semesters for the 2021-2022 school year.
Please look for your summer mailer through the US Postal Service to arrive early in July. I encourage you to read all the documents enclosed, and make sure that all the forms in the registration packet are completed and ready to be turned in during our summer spirit days. 
Spirit Days (Schedule Pickup) for the upcoming school year are scheduled for July 26, July 27, and July 28. Please see the schedule below for the dates and times your class is scheduled to attend.  
Seniors Tuesday, July 26th 8:00am - 11:00am
Juniors Tuesday, July 26th 12:0pm - 3:00pm
Sophomores Wednesday, July 27th 12:00pm  - 3:00pm
Freshmen (Last Names A-M) Wednesday, July 27th 8:00am - 11:00am
Freshmen (Last Names N-Z) Thursday, July 28th 8:00am - 11:00am
As we progress with in-person instruction, I cannot stress enough how important it is for our families to maintain an open means of communication. Your engagement with Ontario High School helps foster the relationship needed to support your student’s achievement. I encourage you to get involved with ELAC, School Site Council, Coffee with the Principal or other stakeholder groups. For more information on where you can get involved, please contact the school, and ask for Mrs. Leticia Morales, Assistant Principal of Student Achievement.
Ontario Jaguar families, I am excited and look forward to the 2022-23 school year. We are here to support you, encourage you, and push you to great heights. I am excited to begin the year with you. 
Go Jags!!
Larry Rook
Principal, Ontario High School