86th is the ordinal form of the number 86. 86th or Eighty-sixth may also refer to:
A fraction, , equal to one of 86 equal parts
Geography 86th meridian east, a line of longitude 86th meridian west, a line of longitude 86th parallel north, a circle of latitude 86th parallel south, a circle of latitude 86th Street (disambiguation)
Military 86th Brigade (disambiguation) 86th Division (disambiguation) 86th Regiment (disambiguation)
Other 86th century 86th century BC
See also 86 (disambiguation)