Banyai or Bányai is a surname. Notable people with the surname include:
Ágoston Bányai (born 1950), Hungarian rower Gábor Bányai (born 1969), Hungarian parliamentarian Istvan Banyai (1949–2022), Hungarian illustrator and animator Júlia Bányai (1824–1883), freedom fighter Márk Bányai (born 1999), Romanian-Hungarian water polo player Nándor Bányai (1928–2003), Hungarian football player and manager