Isayev (Russian: Иса́ев; masculine) or Isayeva (Иса́ева; feminine), also spelled Isaev, is a Russian language family name which means "(son) of Isay", with Isay (Иса́й) being the Russian given name that corresponds to "Isaiah".
Isayev may refer to one of the following:
- People
- Aleksei Mihailovich Isaev, Russian rocket engineer
- Nikita Isayev (born 1984), Ukrainian lawyer
- Ali Isayev (born 1983), Azerbaijani wrestler
- Anatoli Isayev (born 1932), Soviet/Russian soccer player and coach
- Arif İsayev (born 1985), Azerbaijani soccer player
- Grigory Isayev, Russian politician
- Pyotr Isayev, better known as Petka, the aide-de-camp of Vasily Chapayev
- Magomet Isayev (born 1928), Russian Esperantist
- Maxim Isayev, fictional Russian spy in Nazi Germany working under his undercover name of Max Otto von Stierlitz
- Sergei Isayev (born 1983), Russian soccer player
- Shamil Isayev (born 1964), retired Russian soccer player
- Vladimir Isayev, several people
- Other
- Isaev (crater), a lunar crater
- Isayev S-125, a Soviet surface-to-air missile system
- Isayev, name of several rural localities in Russia