Radonjić (Serbian Cyrillic: Радоњић) is a Serbian surname, a patronymic derived from the given name Radonja.

Notable people with the surname include:

• Andrea Radonjić (born 1994), Montenegrin beauty pageant titleholder who was crowned Miss Montenegro Universe 2011 and represented her country in the 2012 Miss Universe
• Dejan Radonjić (born 1970), Montenegrin former professional basketball player and current head coach
• Goran Radonjić (born 1983), Montenegrin heavyweight kickboxer, captain of Montenegrin kickboxing team
• Jovan Radonjić (1748–1803), guvernadur of Montenegro between 1764 and 1803
• Kristina Radonjić (born 1974), Serbian rhythmic gymnast who competed as Independent Olympic Participant at the 1992 Summer Olympics
• Miljko Radonjić (1770–1836), Serbian writer, professor at the Belgrade Higher School and politician
• Nemanja Radonjić (born 1996), Serbian football forward who plays for Olympique de Marseille
• Nenad Radonjić (born 1996), Serbian football forward who plays for Radnički Beograd, on loan from Voždovac
• Srđan Radonjić (born 1981), Montenegrin former professional footballer who played as striker
• Staniša Radonjić (1650s–1720s), Serbian Orthodox priest, chieftainvojvoda of the Njeguši tribe, and serdar of the Prince-Bishopric of Montenegro
• Stanislav Radonjić (1690–1758), vojvoda, serdar and the first guvernadur (governor) of the Prince-Bishopric of Montenegro from 1756 until he died in 1758, serving Metropolitan Sava II Petrović-Njegoš
• Vladan Radonjić (born 1979), Serbian professional strength and conditioning coach
• Vukolaj Radonjić (1765–1832), last Montenegrin guvernadur