Thirteenth or 13th may refer to:
Ordinal form of the number 13 (number). A fraction, , equal to one of 13 equal parts Thirteenth (interval)
Popular culture 13th (film), a 2016 documentary on the Thirteenth Amendment to the United States Constitution 13th (TV series), 2025 Indian television series "The 13th", a song from Wild Mood Swings by The Cure "The Thirteenth" (Orange Is the New Black), a 2019 television episode Thirteenth (fairy tale), an Italian fairy tale from Sicily
Geography 13th meridian east, a line of longitude 13th meridian west, a line of longitude 13th parallel north, a circle of latitude 13th parallel south, a circle of latitude Thirteenth Avenue (disambiguation) 13th Street (disambiguation)
Military Thirteenth Army (disambiguation) 13th Battalion (disambiguation) 13th Brigade (disambiguation) 13th Division (disambiguation) 13th Regiment (disambiguation) 13th Squadron (disambiguation)
Other Thirteenth Amendment (disambiguation) Thirteenth Amendment to the United States Constitution 13th century 13th century BC Thirteenth of the month, a recurring calendar date Friday the 13th
See also 13 (disambiguation)