Kaas is a surname. Notable people with the surname include:
Carl Waaler Kaas (born 1982), Norwegian orienteering competitorErling Kaas (1915-1996), Norwegian pole vaulterHerman Munthe-Kaas (1890-1977), Norwegian architectHugo Munthe-Kaas (1922-2012), Norwegian intelligence agent and resistance fighterJon Kaas, professor and scientistLudwig Kaas (1881-1952), Roman Catholic priest and German politicianNiels Kaas (1535-1594), Danish 16th century politician and diplomatNikolaj Lie Kaas (born 1973), Danish actorPatricia Kaas (born 1966), French singer and actressPreben Kaas (1930-1981), Danish actor