Anaïs Nin (1903-1977), French-born author and diarist

Nine Inch Nails, an American rock band

National identification number

Joaquin Nin-Culmell (1908-2004), Cuban-Spanish composer

Nin, Croatia

Andrés Nin (1892-1937), Spanish revolutionary

Nion or Nin, a letter in the Ogham alphabet

NIN (magazine), a Serbian political magazine

Khadja Nin (born 1959), Burundian singer

Joaquin Nin (1859–1949), Cuban pianist and composer