Gell-Mann was born in lower Manhattan into a family of Jewish immigrants from the Austro-Hungarian Empire, specifically from Chernivtsi in present-day Ukraine. His parents were Pauline (née Reichstein) and Arthur Isidore Gell-Mann, who taught English as a Second Language (ESL).
Propelled by an intense boyhood curiosity and love for nature and mathematics, he graduated valedictorian from the Columbia Grammar & Preparatory School and subsequently entered Yale College at the age of 15 as a member of Jonathan Edwards College. At Yale, he participated in the William Lowell Putnam Mathematical Competition and was on the team representing Yale University (along with Murray Gerstenhaber and Henry O. Pollak) that won the second prize in 1947. Gell-Mann earned a bachelor's degree in physics from Yale in 1948 and a PhD in physics from Massachusetts Institute of Technology (MIT) in 1951. His supervisor at MIT was Victor Weisskopf.
In 1958, Gell-Mann and Richard Feynman, in parallel with the independent team of George Sudarshan and Robert Marshak, discovered the chiral structures of the weak interaction in physics. This work followed the experimental discovery of the violation of parity by Chien-Shiung Wu, as suggested by Chen Ning Yang and Tsung-Dao Lee, theoretically.
Gell-Mann's work in the 1950s involved recently discovered cosmic ray particles that came to be called kaons and hyperons. Classifying these particles led him to propose that a quantum number called strangeness would be conserved by the strong and the electromagnetic interactions, but not by the weak interactions. Another of Gell-Mann's ideas is the Gell-Mann–Okubo formula, which was, initially, a formula based on empirical results, but was later explained by his quark model. Gell-Mann and Abraham Pais were involved in explaining several puzzling aspects of the physics of these particles.