Millennium is a series of best-selling and award-winning Swedish crime novels, created by Stieg Larsson. The two primary characters in the saga are Lisbeth Salander, a woman in her twenties with a photographic memory and poor social skills, and Mikael Blomkvist, an investigative journalist and publisher of a magazine called Millennium.

Larsson planned the series as having ten installments, but due to his sudden death in 2004, only three were completed and published.[1][2] All of them were published posthumously: The Girl with the Dragon Tattoo in 2005, The Girl Who Played with Fire in 2006, and The Girl Who Kicked the Hornets' Nest in 2007.

The series was originally printed in Swedish by Norstedts Förlag, with English editions by Quercus in the United Kingdom and Alfred A. Knopf in the United States. The books have since been translated and published by many publishers in over fifty countries. As of March 2015, 80 million copies of the three books have been sold worldwide.

A fourth book, The Girl in the Spider's Web, commissioned by the publisher Norstedts to continue the series, was published in August 2015. The book is based on Larsson's characters and was written by the Swedish author and crime journalist David Lagercrantz. A fifth installment, The Girl Who Takes an Eye for an Eye, will be published on September 7, 2017