The University of Delaware (colloquially known as UD, UDel, or Delaware) is a privately governed, state-assisted land-grant research university in Newark, Delaware, United States. UD offers 4 associate programs, 163 bachelor's programs, 136 master's programs, and 64 doctoral programs across its ten colleges and schools. The main campus is in Newark, with satellite campuses in Dover, Wilmington, Lewes, and Georgetown, Delaware. With 24,221 students as of fall 2023, UD is the largest university in Delaware by enrollment.

UD is classified among "R1: Doctoral Universities – Very high research activity". According to the National Science Foundation, UD spent $186 million on research and development in 2018, ranking it 119th in the nation.

UD students, alumni, and sports teams are known as the "Fightin' Blue Hens", commonly shortened to "Blue Hens", and the school colors are Delaware blue and gold. UD sponsors 21 men's and women's NCAA Division I sports teams and have competed in the Coastal Athletic Association (CAA) since 2001 except for the men's hockey team which competes in the ESCHL. The university has left the CAA and subsequently joined Conference USA for the 2025–2026 academic year.