Gretchen A. Whitney High School, called Whitney High School or WHS, is a public school in Cerritos, California serving grades 7–12. It is in the ABC Unified School District. According to US News Report, as of 2023, Whitney High School is ranked 2nd in the state of California and ranked 17th nationally among all high schools.

Whitney High School was founded on September 25, 1975 (under the name Gretchen A. Whitney Learning Center) as a community academic learning center. It was created by ABC superintendent Charles Hutchison, who envisioned Whitney to be a vocational school. The school refocused as an academic magnet/collegiate preparatory school. As a tribute to Hutchison, the current cafeteria is named the Hutch.

In 1997, half of Whitney's parking lot was purchased by a housing contractor to build a gated community adjacent to Whitney. In exchange, Whitney received funds to construct a gymnasium. In 2012, Whitney built a multi-media arts center featuring computer labs and a theater.

In 2018, Measure BB was passed. The school used the funding to provide for major technology renovations and the construction of a new science-focused building.

The school briefly went into lockdown in March 2023 due to a threat of a bomb in the school in a call to the local police department. No one was injured.

Admission into Whitney is determined through mandatory placement testing. Students in elementary school are automatically tested during their sixth grade year, while students already in middle school or high school are required to take an additional writing test. Admissions are determined primarily through the California Assessment of Student Performance and Progress, with an additional criterion being the universally mandated essay examination.

Whitney's curriculum, as of September 2019, included 15 Advanced Placement courses and 35 Honors courses, though students who attended Whitney High School were automatically placed in honors courses, except for math and physical education courses.

In 1991, Whitney was recognized with the Department of Education's National Recognition Award as a Blue Ribbon School. Senator John F. Seymour spoke on the US Senate floor to recognize the school. Whitney is one of the three Blue Ribbon Lighthouse Schools Charter Members. The school was again honored as a Blue Ribbon school in 1998, 2003, 2008, and 2014. Whitney became the first school to receive 5 Blue Ribbon Awards. President George W. Bush's brother Neil, co-founder of an educational software company, has visited the campus several times, as he put it, "because of the respect the staff has for students. I’ve never seen anything like it. Every school should be this way."

Whitney has been honored with the California Distinguished School title six times: 1986, 1990, 1992, 1996, 2003, and 2007.

In 2005, the Associated Press rated Whitney High the best high school in California, based on its Academic Performance Index (API) score.

Whitney High has been featured in a special report done by Fox News in 2005. The report on mentoring featured Whitney's "Big Buddy/Little Buddy" system. Furthermore, CBS News's "Weekend Journal" also reported on Whitney, focusing on the public high school's academic achievements.

In 2006, the school was on Newsweek’s "America's Best High School" list. Whitney was not included in the top 100 high schools because "so many of [Whitney's] students score well above average on the SAT and ACT". However, Newsweek did include Whitney in "The Public Elites" section, and labeled Whitney as "a comprehensive school for high performers". Newsweek again recognized Whitney in the May 23, 2007 "America’s Best High School" edition. Similar to the 2006 edition, Whitney was included as 1 of the 19 "The Public Elite" high schools and was labeled as an "award-winning school with special emphasis on college admissions".

The passing rate for the California High School Exit Exam (CAHSEE) for Whitney students is 100%. Whitney received a six-year accreditation from the Western Association of Schools and Colleges (WASC) in 2004.

Business Week declared Whitney as having the "Best Overall Academic Performance" in 2009 for California.

U.S. News & World Report ranked Whitney High School as the No. 12 high school in the nation in the November 30, 2007 edition. Whitney was ranked No. 10 in the December 15, 2008 edition. Whitney was ranked the 3rd best high school in America for 2010 in the December 10, 2009 edition. Whitney was 1st in the state of California for 2016, and rank 19th nationally. Whitney was 1st in the state of California for 2018.

Newsweek ranked Whitney High School as the No. 4 high school in the nation in September 2014.

Whitney High is part of the CIF Division IV, and the mascot is the Wildcat. In its earliest years WHS did not have any school athletics at all, and they gradually added small sports teams in later years.

Whitney High is now part of the newly formed 605 league, Division 3, CIF Southern Section.

The WHS Yearbook won First Place and Outstanding Theme at the 2013 American Scholastic Press Association Yearbook Competition.

WHS's award-winning robotics team participates in FIRST: For Inspiration and Recognition of Science and Technology, an organization founded in 1989 by Dean Kamen and Woodie Flowers to motivate young people in their schools and communities to reach an appreciation of science and technology. Currently the team competes in the FIRST Tech Challenge (FTC), and FIRST LEGO League (FLL). Students also participate in outreach programs in robotics with local elementary schools, community groups, and summer RoboCamps.

Students have the opportunity to debate national issues in the Junior Statesmen of America program with other students from southern California.

"It's Finally Friday" (a.k.a. "IFF") is a televised show broadcast over the school's television network every Friday, from September 2003 and until June 2005, and brought back from 2006 to 2008.

The Whitney Independent News Network was founded during the 2009 – 2010 school year.

In 2009, the school ceased publishing Aspects, the student newspaper. In 2018, the school newspaper was brought back by the Newspaper Club and is called The Wildcat's Tale.

"Whitney High School Live" is Whitney's news program that airs three times a week during homeroom. It began in the 2014–2015 school year.

Whitney High is the subject of School of Dreams, a book written by the Pulitzer prize-winning journalist Edward Humes and published in September 2003. Humes spent the 2001–2002 school year at Whitney teaching a writing workshop, and used his case study of Whitney High to bring national attention to the pressures endured by the students of America's magnet schools.

• Terisa Greenan - film producer, director, and actress
• Julie Su - United States Deputy Secretary of Labor, acting United States Secretary of Labor
• Nancy Wang Yuen - sociologist, Professor of Sociology at Biola University

• Official web site
• Whitney High page at BlueRibbonSchools.com Archived February 3, 2007, at the Wayback Machine
• Newsweek America's Best High Schools