64 or sixty-four may refer to:

• 64 (number), the natural number following 63 and preceding 65

• one of the years 64 BC, AD 64, 1964, 2064

• Highway 64, see list of highways numbered 64
  • Interstate 64, a national route in the United States
• The code for international direct dial calls to New Zealand (+64)

• "64" (song), a 2011 song by hip hop band Odd Future
• Sixty Four (album), a 2004 album recorded in 1964 by Donovan
• "64" is the title of a song by the hip-hop group Mellowhype from their album BlackenedWhite

• The atomic number of gadolinium, a lanthanide
• 64 Angelina (asteroid 64), a main-belt asteroid

• Base64 encoding
• Commodore 64 (in 8-bit home computers, a common shorthand is 64)
• A /64 Classless Inter-Domain Routing block

• Nintendo 64, a 1996 video game console
• 64, a Russian chess magazine
• Sixty-four (ship), a type of sailing warship
• Crayola 64 pack
• 64 Zoo Lane, a British animated children's TV series
• Porsche 64, a race car derived from the Volkswagen Beetle
• The international calling code for New Zealand
• A number used to represent the Tiananmen Square protests and massacre.

• All pages with titles beginning with 64
• All pages with titles containing 64
• All pages with titles containing sixty-four
• 64th (disambiguation)
• 64DD, Nintendo 64 video game accessory