Zajonc or Zayonc (Polish pronunciation: ['zajɔnts]) is a surname. It is a spelling variant of Zając, meaning "hare" in Polish. Notable people with the surname include:

• Arthur Zajonc (born 1949), American physicist and writer
• Miroslav Zajonc or Miro Zayonc (born 1960), American luger
• Rick Zayonc (born 1959), Canadian water polo player
• Robert Zajonc (1923–2008), American social psychologist

• Inga Zajonc, "Polish beauty", childhood friend of Ostap Bender

• All pages with titles containing Zajonc
• All pages with titles containing Zayonc
• 32294 Zajonc, a main belt asteroid
• Jeffrey Zients (born 1966), an American business executive and government official