Gagarin (), or Gagarina (feminine; Гагарина), is a Russian surname derived from the word gagara, meaning loon (a waterbird, genus Gavia). Notable people with the surname include:
Yuri Gagarin (1934–1968), Russian cosmonaut, the first man to travel in space
Gagarin family, a Rurikid princely family Anna Gagarina, maiden name of Anna Lopukhina (1777–1805), mistress of Emperor Paul of Russia Ivan Gagarin (1814–1882), Russian Jesuit theologian Nikolai Gagarin (1784–1842), Russian soldier and politician Grigory Gagarin (1810–1893), Russian painter, major general and administrator Polina Gagarina (born 1987), Russian singer, songwriter, actress, and model Andrey Gagarin (1934–2011), Russian prince and scientist Yekaterina Gagarina (1790–1873), wife of Russian diplomat Prince Grigory Gagarin and the daughter of the Secretary of State Pyotr Soymonov