Sigma Boy is a Russian pop song performed by young singers Betsy and Maria Yankovskaya. Released in 2024, it spread internationally through short-form videos, where its repeated hook inspired dances, edits, parodies, and translations. The Russian title is written as Сигма Бой, while English-speaking users commonly search for Sigma Boy or Sigma Boi. Its simple refrain and association with online sigma slang helped the track remain recognizable beyond its original language and made brief excerpts useful for humorous confidence-themed content.