Concord Academy was founded in 1919 by local residents Anne Bixby Chamberlin, a Wellesley College graduate, and Mrs. Henry F. Smith, Jr.[2] Chamberlin, who had six daughters and two sons, was concerned that the closest high school for girls (Winsor School) was 20 miles away in the city of Boston.

[4] In 1922, Chamberlin and Smith transferred control over the fledgling school to a board of trustees, who reorganized CA as a non-profit corporation.

[7] To raise money, the trustees added a small boarding department, which charged the then-astronomical sum of $1,500 a year.

[13] CA's expansion during this period was fueled almost exclusively by tuition money and project-specific donations; when Hall stepped down in 1963, the financial endowment stood at just $112,000.

[15]) To finance her aspirations for CA, Hall aggressively courted wealthy, high-achieving boarding students from across the globe.

[19] In 1971, Harvard's student newspaper reported that Concord Academy "sits at the top of the pile in terms of popularity.

"[20] In the 1960s and 1970s, Concord Academy was confronted with two major issues: the American upper class' decreasing interest in boarding schools, which caused an industry-wide shortfall of tuition dollars,[20] and the fact that most boys' boarding schools were shifting to coeducation, "which meant that fathers who had attended them could now send their daughters to their alma maters.

[22] CA students had been participating in Groton's theatrical productions (and vice versa) since the 1950s[23] and also attended some of its campus programming,[24] but large-scale academic cooperation had never occurred before.

[26] A two-week exchange program with New Hampshire-based St. Paul's School made The New York Times but did not result in closer cooperation.

[28] Faced with competition for talented girls from the formerly all-boys' schools, CA administrators sought to maintain the quality of the student body by expanding the size of its applicant pool.

A 1996 study found that 29% of CA graduates went on to Ivy League colleges, tied with Phillips Exeter Academy for fifth among Northeastern boarding schools.

Hall Chapel in 1984 and 2004–05,[36][37] the dedication of the J. Josephine Tucker Library in 1987,[37] the opening of expanded athletic facilities in 2012,[38][39] and the reopening of the renovated science center in 2016.

[40] The nation's first Gay-Straight Alliance chapter was established at Concord Academy by history teacher Kevin Jennings in the 1980s.

[43] The current head of school is Henry Fairfax, who began leading Concord Academy in July 2022.

[59] The campus is a short walk from restaurants and shops in Concord, and students have easy access to Cambridge and Boston via commuter rail.