The University of Sussex is a public research-intensive university located in Falmer, East Sussex, England. It lies mostly within the city boundaries of Brighton and Hove. Its large campus site is surrounded by the South Downs National Park, and provides convenient access to central Brighton 5.5 kilometres (3.4 mi) away. The university received its Royal Charter in August 1961, the first of the plate glass university generation.

More than a third of its students are enrolled in postgraduate programmes and approximately a third of staff are from outside the United Kingdom. Sussex has a diverse community of nearly 20,000 students, with around one in three being foreign students, and over 1,000 academics, representing over 140 different nationalities. The annual income of the institution for 2021–22 was £345.2 million with an expenditure of £377.4 million.

Sussex counts 5 Nobel Prize winners, 15 Fellows of the Royal Society, 10 Fellows of the British Academy, 24 fellows of the Academy of Social Sciences and a winner of the Crafoord Prize among its faculty. By 2011, many of its faculty members had also received the Royal Society of Literature Prize, the Order of the British Empire and the Bancroft Prize. Alumni include heads of states, diplomats, politicians, eminent scientists and activists.