Eckhart gained wide recognition as George in Erin Brockovich (2000), and, in 2006, he received a Golden Globe nomination for his portrayal of Nick Naylor in Thank You for Smoking.

In 2008 he played a major role in Christopher Nolan's blockbuster Batman film The Dark Knight as District Attorney Harvey Dent / Two-Face.

He went on to appear in Love Happens, Rabbit Hole, Battle: Los Angeles, The Rum Diary, Olympus Has Fallen and its sequel, I, Frankenstein, Sully, and Midway.

[24] After graduating from BYU, Eckhart moved to New York City, acquired an agent, and took various occasional jobs, including bartending, bus driving, and construction work.

[13][25] Eckhart followed this small part with roles in documentary re-enactments (Ancient Secrets of the Bible: Samson), made-for-television movies, and short-lived programs like Aliens in the Family.

[27] The film, his first feature to reach theaters, was critically well received,[28] with Desson Howe of The Washington Post reporting that Eckhart is the "movie's most malignant presence" and that he "is in chilling command as a sort of satanic prince in shirtsleeves".

[33] The following year Eckhart starred in another LaBute feature, Your Friends & Neighbors (1998),[20][23] as Barry, a sexually frustrated husband in a dysfunctional marriage.

[34] In 1999, he starred opposite Elisabeth Shue in Molly, a romantic comedy-drama in which he played the self-absorbed brother of an autistic woman who was cured by surgery.

[36] Eckhart first gained wide exposure in 2000 as George, a ponytailed, goateed biker, in Steven Soderbergh's drama Erin Brockovich.

[39] His performance was well received by critics; Entertainment Weekly's Owen Gleiberman wrote that Eckhart "may be playing a bit of an ideal [...] but he makes goodness as palpable as he did yuppie evil in 'In the Company of Men'.

[45] In 2003, Eckhart co-starred with Hilary Swank in The Core, a film about a geophysicist who tries to detonate a nuclear device in order to save the world from destruction.

[41][61] In 2005, returning to film, Eckhart appeared in Neverwas as a therapist who takes a job at a rundown mental hospital that once treated his father (Nick Nolte).

"[69] In the Seattle Post-Intelligencer review of the film, it was reported that "Under his chummy but compassionless smile" Eckhart radiated charm and "Naylor's true joys: manipulating arguments, steering debate, cooking words.

[82] Eckhart starred in the 2008 comedy Meet Bill, in which he played the eponymous character, a sad executive working at his father-in-law's bank.

[26][85] Also in 2008, Eckhart portrayed the comic book character Harvey Dent in Christopher Nolan's The Dark Knight, the sequel to the 2005 film Batman Begins.

[86][87] Nolan's decision to cast Eckhart was based on his portrayal of corrupt characters in the films In the Company of Men, The Black Dahlia, and Thank You For Smoking.

"[88][89] The Dark Knight was a big financial and critical success, setting a new opening weekend box office record for North America.

Roger Ebert opined that Eckhart did an "especially good job" as his character in the feature,[92] while Premiere magazine also enjoyed his performance, noting that he "makes you believe in his ill-fated ambition ... of morphing into the conniving Two-Face.

"[93] Following the success of The Dark Knight, Eckhart next appeared in Alan Ball's Towelhead (2008), an adaption of the Alicia Erian novel of the same name, in which he played a Gulf War Army reservist who sexually abuses his 13-year-old Arab-American neighbor.

[105] In 2011, Eckhart starred in Jonathan Liebesman's science fiction film Battle: Los Angeles, in which he portrayed a combat veteran Marine platoon sergeant.

[106] He appeared alongside Johnny Depp, Richard Jenkins, and Amber Heard in Hunter S. Thompson's novel adaptation The Rum Diary, directed by Bruce Robinson.

[107][108] In the film, Eckhart played Sanderson, a wealthy landowner, who believes everything has a price and introduces Paul Kemp (Depp) to a different standard of living.

[60] Eckhart has noted that hypnosis helped him to quit drinking, smoking, and partying,[4][112] and that he undertakes amateur photography in his spare time.