Cassian

• St. Cassian of Imola (4th-century–363), Christian martyr
• St. Cassian of Autun (died 350), Christian bishop of Autun
• St. John Cassian the ascetic (360–435), French Christian saint and author
• St. Marcellus the Centurion, martyr of Tingis, sometimes called "Cassian"
• Cassian Sakowicz (1578–1647), Orthodox activist and, later, a Catholic theologian, writer, and polemicist
• Cassian of Tangier (3rd-century–298), Christian saint

• Cassian Elwes (born 1959), British film producer
• {{ill|Cassian (Yaroslavsky)|ru|Кассиан (Ярославский)}} (1899–1990), Russian Orthodox bishop

• Ed Cassian (1867–1918), former Major League Baseball player
• George Cassian, (1932-1979) Canadian yacht designer
• Nina Cassian (1924–2014), Romanian writer
• Brigant Cassian (1889–1957), priest and education worker in Hong Kong

• Cassian Andor, a character in the Star Wars franchise
• Cassian, a character in Sarah J. Maas's book series A Court of Thorns and Roses

• Cassian, Wisconsin, U.S.
• Cassian River, Quebec, Canada

• Cassian (stage), a geochronologic name in Italian stratigraphy
• Sabinian school, known as the Cassians

• {{intitle|Cassian}}
• Kassian

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