Cas may refer to:
Caș, a type of cheese made in Romania
Čas (1886–) Czech magazine associated with Tomáš Garrigue Masaryk
Čas (19 April 1945–February 1948), the official, daily newspaper of the Democratic Party of Slovakia
CAS, a 2018 album by Lúnasa, an Irish Celtic band
Cas (people), an ancient people near the Caspian Sea
Cas (name), a list of people (and a mythological hero) with the given name, nickname or surname
Cas guava (Psidium friedrichsthalianum), a Costa Rican guava species
Cas Cay, an island in St. Thomas, United States Virgin Islands
Cassiopeia (constellation), standard astronomical abbreviation
Castleford, town in West Yorkshire know colloquially as Cas
CRISPR-associated proteins, proteins involved in prokaryotic antiviral defense and gene editing
CAS Registry Number, a unique identification number, assigned by the Chemical Abstracts Service in the US to every chemical substance
Chemical Abstracts Service (CAS)
