Highlander II: The Quickening is a 1991 science fiction film directed by Russell Mulcahy and starring Christopher Lambert, Virginia Madsen, Michael Ironside and Sean Connery. It is the second installment in the Highlander film series and sequel to the 1986 fantasy film Highlander. Set in the year 2024, the plot concerns Connor MacLeod, who regains his youth and immortal abilities and must free Earth from the Shield, an artificial ozone layer that has fallen under the control of a corrupt corporation.

The film was shot almost entirely in Argentina before and after the country's economy crashed; as the local economy experienced hyperinflation, the film's investors and completion bond company took direct control of production and final edit, removing director Mulcahy and his creative influence while changing parts of the story. The resulting film contradicts the established canon of Highlander, in depicting immortals as aliens, featuring the inexplicable resurrection of Juan Sánchez-Villalobos Ramírez, and altering the concept of the "Quickening".

Highlander II was panned by critics and fans, and is considered to be one of the worst films ever made. The original theatrical edition was released on 12 April 1991 in the United Kingdom (in an eight-minute longer cut) and 1 November 1991 in the United States, and was also a box-office bomb grossing $16 million in the US on a production budget of $34 million.

In 1995, an alternate director's cut called the Renegade Version was released to home video that attempted to address the many story problems, such as removing all mention of Zeist and the idea that immortals are aliens. This was followed by a Special Edition DVD release in 2004, which was largely the same cut as the Renegade Version but with some altered special effects. The sequel Highlander III: The Sorcerer follows the events of the first film, in the process contradicting and completely ignoring the events and revelations of Highlander II.