DiCaprio began seeing the Victoria's Secret model in December 2011 after previously dating Blake Lively and supermodel Gisele Bundchen.
Now US Weekly reports that the pair have split due to their work commitments putting a strain on the relationship.
A source told the magazine: "They split a few weeks ago... there's no bad blood - they still care about each other a lot.
"They're both just really busy, they had crazy schedules... They still love and respect each other very much, it was just time to move on."
DiCaprio will next appear in Quentin Tarantino's Spaghetti Western Django Unchained, before starring in Martin Scorsese's crime drama The Wolf of Wall Street.
Watch Leonardo DiCaprio in the trailer for Django Unchained below: