Željko Ivanek is a Slovenian-American actor. Known for his work in film, television, and theatre, he is the recipient of a Primetime Emmy Award, a Screen Actors Guild Award, and a Drama Desk Award, as well as three Tony Award nominations.

Ivanek's film credits include Courage Under Fire (1996), Donnie Brasco (1997), Hannibal, Black Hawk Down (both 2001), Unfaithful (2002), The Manchurian Candidate (2004), Live Free or Die Hard (2007), The Bourne Legacy, Argo, Seven Psychopaths (all 2012), and Three Billboards Outside Ebbing, Missouri (2017). He has appeared in several films by Lars von Trier: Dancer in the Dark (2000), Dogville (2003), and Manderlay (2005).

On television, Ivanek is known for playing Ray Fiske on the FX series Damages (2007–2010), for which he won the 2008 Primetime Emmy for Outstanding Supporting Actor. He also appeared as Ed Danvers on Homicide: Life on the Street (1993–1999) and Russell Jackson on the CBS drama Madam Secretary (2014–2019), and has had recurring roles on series such as Oz (1997–2003), 24 (2002), True Blood (2008), Heroes (2009), Big Love (2009–2010), Banshee (2014), and 12 Monkeys (2015–2017). Since 2023, he has starred as "The Croat" on AMC's The Walking Dead: Dead City.