Ungar is a surname. Notable people with the surname include:
Benjamin (Benji) Ungar, an American Épée fencerDavid Ungar, an American engineerHermann Ungar (1893 – 1929), a Bohemian writer of German language and an officer in the Ministry of Foreign Affairs of CzechoslovakiaJay Ungar, an American musician and composerShmuel Dovid Ungar (1886 – 1945), Rav of Nitra, SlovakiaSimon Ungar (1864 – 1942), rabbi of the Osijek Jewish CommunityStu Ungar (1953 – 1998), a professional poker and gin rummy playerWilliam Ungar (1913 – 2013), founder of the National Envelope Corporation