Casis or Casís is a surname. Notable people with this name include:
Ana Casís, Panamanian sociologist, statistician, and demographer Jazminne Casis, Australian gymnast in 2012 Pacific Rim Gymnastics Championships – Women's Artistic Gymnastics Julio Súmar Casis (born 1931), Peruvian chess player Luis Casis, Panamanian politician, vice-presidential candidate in 2019 Panamanian general election Tomasa Ester Casís (1878–1962), Panamanian teacher and women's rights activist
See also Center for the Advancement of Science in Space (CASIS), managing organization for the International Space Station