53 may refer to:53 (number), the natural number following 52 and preceding 54 one of the years 53 BC, AD 53, 1953, 2053 FiftyThree, an American privately held technology company that specializes in tools for mobile creation and visual thinking 53rd Regiment Alabama Cavalry 53rd Regiment of Foot (disambiguation) 53rd Division (disambiguation) 53 , 2019 "Fifty Three", a song by Karma to Burn from the album Arch Stanton, 2014 Fifth Third Bank 53 Kalypso, a main-belt asteroid Cuba's international calling code DNS over UDP and TCP port 53 (Do53)