A selective admissions program was initiated in 1985 through the cooperation of state and county governments and corporate sponsorship from the defense and technology industries.

[15] Hazleton Laboratories (now Fortrea), Honeywell, AT&T, Dominion Energy, Sony Corporation, Hewlett-Packard, Xerox, and other companies made contributions in equipment or finances to the school before it opened.

[16][9] Thomas Jefferson High School for Science and Technology opened in fall 1985 with 400 ninth-graders and 125 seniors who were selected from 1,200 applicants.

[16] From 2013 to 2017, the school underwent renovations, adding additional research labs, internet cafes, three-dimensional art galleries, a black box theater, and a dome reminiscent of President Thomas Jefferson's Monticello.

[19] In the 2020s, Thomas Jefferson High School for Science and Technology (TJHSST) underwent three major controversies regarding its admissions process,[6] intentionally delayed distribution of National Merit awards,[20] and its relationship with Chinese entities.

[21] The school replaced its test-based admissions with a holistic review process in 2020, leading to significant demographic changes and legal challenges.

[23][21] Amidst these controversies, Principal Ann Bonitatibus resigned in October 2024;[24][25] she stated in an email to parents that she had "pursued and accepted" a "promotion" to the Fairfax County Public Schools' Human Resources department, which drew widespread skepticism.

[43][44] In 2012, a civil rights complaint against the school was filed with the U.S. Department of Education Office of Civil Rights by Coalition of the Silence, an advocacy group led by former county School Board member Tina Hone, and the Fairfax chapter of the NAACP, alleging that it discriminated against black, Hispanic, and disabled students.

[47][48] In 2020, the school board made a number of significant changes to the admissions process meant to increase the ratio of black and Hispanic students admitted.

[37] In March 2021, the Coalition for TJ, an advocacy group opposed to the changes and represented by the Pacific Legal Foundation, sued the Fairfax County school board, alleging that the 2020 changes to the admissions process discriminated against Asian Americans.

[54] TJ's curriculum is focused on college preparation and provides students with the opportunity to achieve in all disciplines, with an emphasis on science and technology.

[55] The Systems Engineering Course designed and built a CubeSat which was launched on November 19, 2013, from Wallops Flight Facility in Virginia.

[56] The launched satellite contained a 4-watt transmitter operating on amateur radio frequencies, and a text-to-speech module to allow it to broadcast ASCII-encoded messages sent to it from Jefferson.

After a 6-year period of planning, building, and testing from 2016 to 2022 that was interrupted by the COVID-19 pandemic, REVERB was launched aboard SpaceX's CRS-26 on November 26, 2022, at 2:20PM EST.

[64] The lab also supported a number of Sun Microsystems thin clients for use by students enrolled in AP Computer Science.

"[87] This led to an investigation of 17 Virginia schools and prompted Governor Glenn Youngkin to propose legislation mandating immediate notification of such opportunities to parents and students.