Connie Nielsen is a Danish actress. She was born in Copenhagen, Denmark to an insurance clerk mother and a bus driver father. She was raised in a small seaside village named Elling. She began her acting career working alongside her mother on the local revue and variety scene. At 18 she travelled to Paris, France where she worked as an actress and model, which led to further work and study in Italy — at drama school in Rome and in master classes with Lydia Styx, a teacher at il Piccolo Teatro di Milano in Milan. She lived in Italy for many years, before moving to the United States, where she still resides.

Nielsen's feature film debut was the Jerry Lewis French film, Par Où T'es Rentré? On T'a Pas Vu Sortir in 1984, followed by a role in the Italian mini-series Colletti Bianchi in 1988. She appeared in the 1991 Italian Vacanze di Natale '91 and the French film Le Paradis Absolument in 1993.

She moved to the United States in 1996 and made her first appearance in a major English-language film in 1997 as Christabella Andreoli in The Devil's Advocate, starring opposite Al Pacinoand Keanu Reeves in a somewhat "revealing" role. This led to roles in films as Permanent Midnight (1998), Rushmore (1998) and Soldier (1998).

In 2000, Nielsen became known to worldwide audiences as Lucilla in Ridley Scott's internationally acclaimed Academy Award-winning epic Gladiator, where she starred opposite Russell Crowe and Joaquin Phoenix. She has since then starred in some notable American films, including Mission to Mars (2000), One Hour Photo (2002), The Hunted (2003) and Basic (2003). She also starred in the acclaimed French thriller Demonlover (2002), directed by Olivier Assayas.

In 2004, Nielsen made her Danish film debut in the drama, Brødre (aka Brothers) for which she won the Danish Best Actress Award, The Bodil, as well as Best Actress at the San Sebastian International Film Festival. She was also nominated for Best Actress at the European Film Awards. In 2006, Nielsen appeared in several episodes of Law & Order: Special Victims Unit as Det. Dani Beck She filled in for Mariska Hargitaywho was on maternity leave at the time of filming.