[citation needed] Sklenar graduated in 2008 from Hackettstown High School and enrolled briefly at County College of Morris before heading out to California after two months, adopting his mother's surname for acting purposes.

[16][17] Sklenar received positive critical acclaim from multiple media outlets for his performance in Mapplethorpe, including from Boy Culture, who praised him for "[having] maximum impact in [his] psychologically charged scenes with [Matt] Smith"[18] He appeared in the 2018 biographical drama film, Vice, opposite Amy Adams, Steve Carell, Christian Bale and Sam Rockwell.

That same year, Sklenar was cast as the lead antagonist in The Big Ugly, a noir crime thriller that weaves the British gangster genre with the American Western, opposite Ron Perlman, Malcolm McDowell, Nicholas Braun and Leven Rambin.

Richard Roeper of the Chicago Sun Times stated, "Brandon Sklenar gives a screen-popping performance as Junior; he's fantastic as a monster cloaked in a James Dean persona.

He then starred in the independent film Jonesin' – a crime comedy about a moonshiner who, after a case of mistaken identity, gets abducted and finds himself stuck in the city between two rival gangs.