Haidai (surname)

Haidai or Gaidai (Гайдай), also transliterated Hayday and Gayday, is a surname. Notable people with the surname include:


 * Leonid Gaidai (1923–1993), Soviet film director
 * Serhiy Haidai (born 1975), Ukrainian politician
 * Zoia Gaidai (1902–1965), Ukrainian opera singer