Ilyin or Ilin (Russian: Ильин) is a Russian masculine surname that is derived from the male given name Ilya and literally means Ilya's. its feminine counterpart is Ilyina or Ilina. It may refer to

• Aleksandr Ilyin (disambiguation), several people
• Aleksei Ilyin (disambiguation), several people
• Alin Ilin (born 1984), Romanian football player
• Anatoli Ilyin (1931–2016), Soviet Russian football player
• Andrey Ilin (born 1960), Russian film and theatre actor
• Dmitry Ilyin (born 1984), Russian fine art and documentary street photographer
• Efraim Ilin (1912–2011), Israeli tycoon and security expert
• Fyodor Ilyin (1892–1939), Soviet admiral and diplomat
• Gleb Ilyin (1889–1968), Russian-American painter
• Ilya Ilin (born 1988), Kazakhstani weightlifter
• Ivan Ilyin (1883–1954), Russian religious and political philosopher
• Kostiantyn Ilin (born 1975), Ukrainian strongman competitor
• Lev Ilyin (1880–1942), Russian architect
• Mikhail Ilyin (1903–1981), Soviet art historian and Moscow expert
• Natalya Ilina (born 1985), Kazakhstani handball player
• Nikolai Ilyin (sniper) (1922–1943), Soviet World War II sniper
• Nikolai Ilyin (Yehowist) (1809–1890), Russian religious thinker and founder of the movement of Yehowists
• Olga Ilina (born 1995), Russian rhythmic gymnast
• Olga Ilyin, Russian-born American poet and novelist
• Sergei Ilyin (born 1968), Russian football player
• Vasily Ilyin (1949–2015), Soviet handball player
• Vera Ilyina (born 1974), Russian diver
• Victoria Ilina (born 1999), Russian rhythmic gymnast
• Viktor Ilyin (born 1947), Russian deserter from the Soviet Army
• Vladimir Ilyin (disambiguation), several people
• Yekaterina Ilyina (born 1991), Russian handball player
• Yuriy (Yuri) Ilyin
  • Yuriy Ilyin (born 1962), Ukrainian Admiral and Chief of the General Staff
  • Yuri Ilyin (born 1968), Kazakhstani politician, Minister of Emergency Situations
• Zoltan Ilin (born 1955), Yugoslavian tennis player