Menlo-Atherton High School (known as M-A to locals) is a four-year public high school secondary school located in Atherton, California. Menlo-Atherton is part of the Sequoia Union High School District.

Menlo-Atherton has been named one of the top secondary schools in the nation by the United States Department of Education as part of its National School Recognition Program. It was selected as a California Distinguished School by the California Department of Education in 2007 and 2013. In 2005, Newsweek ranked the school as the 259th best school in the United States. Menlo-Atherton also offers the most Advanced Placement courses in the district with 24, ranging from Studio Art to US History.

Since the closure of Ravenswood High School, Menlo-Atherton has been racially diverse, drawing from Atherton, Menlo Park, Redwood City, East Palo Alto, and Portola Valley. The school's motto is "Strength in Diversity".

Typically, 97% of graduates continue their education. 37% opt for two-year colleges, 60% go to four-year colleges.

M-A offers the following Advanced Placement courses: Art History; Biology; Calculus AB/BC; Chinese Language; Chemistry; Computer Science A; Computer Science Principles; English Language/Composition; English Literature; Environmental Science; French Language; Latin; Physics; Psychology; Spanish Language; Spanish Literature (approximately every other year); Statistics; Studio Art; and US History. M-A has an 77% pass rate on AP exams, with 41% scoring a 5. It also has the Advanced Via Individual Determination program and the Computer Academy, programs for students seeking a smaller, supportive learning environment.

Menlo-Atherton has nearly 60 teams at the varsity, junior varsity and freshman levels in 15 sports that they offer. Over 46% of the student body participates in a sport with 1,100 athletes in the 2018–19 season. M-A has emerged as one of the most accomplished athletic programs in Northern California, winning 2 CIF State titles (Football & Girls Wrestling-individual title), 8 Central Coast Section titles, and 13 Peninsula Athletic League titles in the 2018–19 school year. The Bears have also won the PAL Commissioner's Cup the last 11 years in a row and in 12 of the 13 years of its existence. The Commissioner's Cup is awarded annually to the Peninsula Athletic League school that best exemplifies the league's commitment to sportsmanship and excellence in athletics. Points are awarded to each varsity team in each sport that they participate in, by the order of finish in league play and for sportsmanship.

In 2017, Co-Athletic Directors Paul Snow and Steven Kryger were named NorCal Athletic Directors of the Year by the California Coaches Association. That same year saw Adhir Ravipati named the NorCal Football Coach of the Year, and in 2018, Jane Worden and Brett Koerten were named State Swim Coaches of the Year, also by the California Coaches Association. In 2017, Menlo-Atherton was named the Northern California Public High School of the Year by Prep2Prep.com for their athletic achievements.

In the 2024 NFL Draft, Menlo-Atherton 2021 alum Troy Franklin was selected as a fourth-round pick and 102nd overall for the Denver Broncos.