In 1995, his dying mother told her son on her deathbed that the man he believed to be his father, in fact wasn't his biological father. Following her death, he tracked down his biological father, a 90-year-old German who after four combative meetings told him that, if he wanted to speak to him again, he could do it through his lawyer.
Broke up with his pregnant wife and moved in with their (much younger) babysitter. 
Added 'von' to his name because his peers at the Danish Film School called him so.
Von Trier's mother, a civil service worker named Inger Høst, confessed shortly before her death that his real father was not Ulf Trier (another ministry worker) but rather her employer, Fritz Michael Hartmann; she explained she wanted a man with "artistic genes," and Hartmann, a member of an illustrious family of Danish composers including Johan Peter Emilius Hartmann and Niels Viggo Bentzon, seemed to fit the bill.
Nephew of filmmaker Børge Høst.
Helped form a collective known as Dogme 95 with a group of other filmmakers. The collective agreed to make films following certain rules, such as using only hand held cameras and shooting only on location.
The year von Trier won the Palme D'Or at the Cannes Film Festival, he almost did not attend the ceremony. He has so many phobias, he could only make the trip in a specially outfitted trailer.
Steven Spielberg offered him the chance to direct a film in America after he saw Europa (1991) but von Trier turned the script down.
He was awarded UNICEF's 'Cinema for Peace Award' at the 2004 Berlinale (Berlin International Film Festival). He got the award because almost all of his films deal with subjects like mercy and ethics.
He was scheduled to direct the four operas of Wagner's Ring at the 2006 edition of the Bayreuth Festival in Germany, but withdrew from the project in 2004 and stated through the festival that he felt that it would exceed his powers and that he did not feel able to fulfil his own ambitions.
Has never visited the US.
Added the "von" to his birth name (Lars Trier) as an homage to director Josef von Sternberg.
Udo Kier is the godfather of his daughter Agnes.
Has said that one of his favourite films is The Philadelphia Story (1940).
Many famous directors and actors have shown their appreciation of von Trier's work. Quentin Tarantino mentions Von Trier's Dogville (2003) as his idea of the best manuscript ever written, Paul Thomas Anderson said he would "carry Lars von Trier's luggage anywhere", Martin Scorsese has Breaking the Waves (1996) listed on his top 10 films of the 90s and Johnny Depp recently said this in a Danish film magazine: "Tell von Trier I'm waiting for an offer, when he is ready, so am I".
He was declared 'persona non grata' at the 2011 Cannes Film Festival after controversial comments during the Melancholia (2011) press conference, which were ironic and intended as biographical jokes, but largely misunderstood by the press and public. In October 2011, five months after the festival, he declared that he would refrain from all future public statements and interviews as a result of the controversy.
He has directed three actresses to the Best Actress Prize at the Cannes Film Festival, Björk for Dancer in the Dark (2000), Charlotte Gainsbourg for Antichrist (2009) and Kirsten Dunst for Melancholia (2011).
Directed one Oscar nominated performance: Emily Watson in Breaking the Waves (1996).
After speaking on a public appearance from Lars Von Trier at the University of Copenhagen, film and media studies, 22/11-06, he expressed interest in making a horror film. It is apparently under development. [November 2006]
He was due in 2007 to begin work on a horror movie, Antichrist, which postulates the Earth was created by Satan rather than God. However, it was reported in May 2007 that he was suffering from depression and might cease film-making altogether. [May 2007]
Shares birthday with Jane Campion and Jacques Audiard. The three directors/writers are all winners of the Palme D'Or at the Cannes Film Festival.
Thirteen moving boxes' worth of material from Lars von Trier's life has been stored in a special collection at the Danish Film Institute library in 2017. Most of the material came from Trier's own basement. Some of it has also been used for an exhibition at Brandts in Odense, Denmark.