Regnell is a Swedish surname. Notable people with the surname include:
Anders Fredrik Regnell (1807–1884), Swedish physician and botanist Elsa Regnell (1889–1967), Swedish Olympic diver Lisa Regnell (1887–1979), Swedish Olympic diver, sister of Elsa Nils Regnell (1884–1950), Swedish Olympic swimmer, brother of Elsa and Lisa