Established in 1971 as the Cambridge Students Union (CSU), it was eventually recognised by the university authorities on May 25th, 1984 and renamed, following a student referendum in March 1985, to Cambridge University Students Union. Its first sabbatical president was Charles Clarke, later a Labour MP and Secretary of State for Education.

The Cambridge University Students Union is often confused with the Cambridge Union Society, the student debating society founded in 1815.

List of CSU/CUSU sabbatical presidents

• 1971-72: Charles Clarke, King's
• 1972-73: Mike Grabiner, King's
• 1973-74: Jill Lewis, Newnham
• 1974-75: Tony Allen Mills
• 1975-76: Alastair Begg
• 1976-77: John Stewart, Downing
• 1977-78: Tom Hayhoe, Corpus Christi
• 1978-79: Charles Birch, Trinity
• 1979-80: Jon Hunt, St. John's
• 1980-81: Iain Wright
• 1981-82: Nick Alexander, Downing
• 1982-83: Ann Robinson, Newnham
• 1983-84: Martin Markus, Trinity Hall
• 1984-85: Chris Thornton, Clare
• 1985-86: Mary Browning, King's
• 1986-87: Michael Black
• 1987-88: Sian Griffiths, New Hall
• 1988-89: Gillian Wilson, St. John's
• 1989-90: Kathryn Robinson, New Hall
• 1990-91: Natalie Ceeney, Newnham
• 1991-92: Bridget Martindale
• 1992-93: Mark Watson, St. Catherine's
• 1993-94: Barney Hamilton, St. John's
• 1994-95: Anna Dixon, Trinity Hall
• 1995-96: Nick Forbes, Selwyn
• 1996-97: Ben Jackson, Emmanuel
• 1997-98: Sarah Bonnett
• 1998-99: Holly Linklater, Jesus
• 1999-00: Tristan Jones, Emmanuel
• 2000-01: Mat Coakley, King's
• 2001-02: Pav Akhtar, Homerton
• 2002-03: Paul Lewis, King's
• 2003-04: Ben Brinded, Gonville & Caius