For many of the scenes involving drinking, the actors and director decided that they would drink for real, and the take that ended up being used in the movie was often the eighth or ninth take, after they had gotten really drunk and their movements and reactions were slower, which can be difficult for an actor to replicate.
Vladimir Vdovichenkov, who played Dmitry, and Elena Lyadova, who played Lilya, started a personal relationship during filming. They got married in early 2015.
When the scene where the mayor visits Nikolay's house and confronts Nikolay and Dmitry was being filmed, Aleksey Serebryakov, who played Nikolay, was so drunk that he became sick and had to leave the scene. Roman Madyanov, who played the drunken mayor, was actually the only one who was sober and he ended up doing much of the scene alone without anyone to act against.
Leviathan (2014) was inspired by the story of Marvin Heemeyer from Granby, Colorado, a welder who owned an automobile muffler repair shop and had a conflict with the town authorities that allowed the construction of a cement manufacturing plant next to his shop in 2001 (as in the documentary Tread (2019)). After his appeals over the decision failed, an outraged Heemeyer armored his bulldozer and used it in 2004 to demolish a number of Granby buildings, including the Town Hall, and shot himself before he could be captured. Director Andrey Zvyagintsev heard the story from his translator in 2008 while filming his segment of New York, I Love You (2008) (the segment was later released as Apocrypha (2009)).
Leviathan (2014) was criticized by the Russian Ministry of Culture---who had provided 35% of its funding---for its negative depiction of ordinary Russians. The Ministry took exception to its picture of Russians as being lazy and hard-drinking, hardly the type of image the country wanted to foster abroad. Despite this, the film was submitted as Russia's entry for the Academy Award for Best Foreign Language Film, and was rewarded with an Oscar nomination.