Ryazantsev or Riazantsev () is a Russian masculine surname, its feminine counterpart is Ryazantseva or Riazantseva. It may refer to
Aleksandr Ryazantsev (born 1986), Russian footballer Alexander Riazantsev (ice hockey) (born 1980), Russian ice hockey player Alexander Riazantsev (chess player) (born 1985), Russian chess grandmaster Maksim Ryazantsev (born 1977), Russian football player Vladislav Ryazantsev (born 1986), Russian politician