81

81 may refer to:

• 81 (number), the natural number following 81 and preceding 82

• one of the years 81 BC, AD 81, 1981, 2081

• The international calling code for Japan

• Nickname for the Hells Angels Motorcycle Club. "H" is the eighth letter of the alphabet, and "A" is the first.

• 81 Terpsichore, a main-belt asteroid

• 81 mm mortar, a military indirect fire weapon

• All pages with titles containing 81

• 81st (disambiguation)

• List of highways numbered 81

• Tatra 81, a heavy-duty truck