Cas

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)