Educated at the School of Drama in Malmö, he became well known for playing police officer Banck in the 1997–1998 Martin Beck TV series and for his leading role in the 2002 film Grabben i graven bredvid.

He was internationally recognized for his role as Mikael Blomkvist in the acclaimed Millennium series and as the lead villains in Mission: Impossible – Ghost Protocol (as Kurt Hendricks) and John Wick (as Viggo Tarasov).

[10] The movie achieved great international success and earned Nyqvist his first Guldbagge Award nomination for Best Actor in a Supporting Role for his portrayal of a misguided husband with anger issues.

[15] In the 2007 film The Black Pimpernel, Nyqvist portrays Swedish ambassador to Chile, Harald Edelstam, who helped many people flee execution by dictator Augusto Pinochet during and after the 1973 Chilean coup d'état.

[22] In 2014, he appeared in John Wick as a New York Russian mob boss who is forced to protect his son from a legendary hit man played by Keanu Reeves.

[23] In one of Nyqvist's final roles, he starred as Russian captain Sergei Andropov, one of only three survivors of a sabotaged submarine in Hunter Killer.

Nyqvist described his childhood, and his quest as an adult to find his biological parents, in his autobiographical novel, Just After Dreaming (Swedish title: När barnet lagt sig).