43rd is the ordinal form of the number 43. 43rd or Forty-third may also refer to:
A fraction, , equal to one of 43 equal parts
Geography 43rd meridian east, a line of longitude 43rd meridian west, a line of longitude 43rd parallel north, a circle of latitude 43rd parallel south, a circle of latitude 43rd Street (disambiguation)
Military 43rd Battalion (disambiguation) 43rd Brigade (disambiguation) 43rd Division (disambiguation) 43rd Regiment (disambiguation) 43rd Squadron (disambiguation)
Other 43rd Amendment 43rd century 43rd century BC 43d Elizabeth, alternative name for the Poor Relief Act 1601
See also 43 (disambiguation)