The University of Massachusetts Amherst (UMass Amherst) is a public land-grant research university in Amherst, Massachusetts, United States. It is the flagship campus of the University of Massachusetts system and was founded in 1863 as the Massachusetts Agricultural College. It is also a member of the Five College Consortium, along with four other colleges in the Pioneer Valley.

UMass Amherst has the largest undergraduate population in Massachusetts with roughly 24,000 enrolled undergraduates. The university offers academic degrees in 109 undergraduate, 77 master's, and 48 doctoral programs in nine schools and colleges. It is classified among "R1: Doctoral Universities – Very high research activity". According to the National Science Foundation, the university spent $211 million on research and development in 2018.

The university's 21 varsity athletic teams compete in NCAA Division I and are collectively known as the Minutemen and Minutewomen. The university is a member of the Atlantic 10 Conference while playing ice hockey in Hockey East and football as an FBS independent school. In July 2025 UMass will join the Mid American Conference as a full member, retaining affiliate status in sports where the MAC does not compete.