It would seem that after you've starred in a blockbuster like "Titanic" it bonds you for life as Elle explains the duo have been each other's biggest champion along the way. In 2013, Kate Winslet is quoted as saying, "Leo has mastered this more than anyone I know. It's not that he's sort of brazen like, 'I don't give a f**k and I'm going to be rebellious and behave badly.' It's not that. It's genuinely not caring what people think because he will not allow other people's judgments to have any kind of impact on his life and who he is. and I have really admired that so much in him."

The Brightside explains that when Winslet married Ned Rocknroll in 2012, DiCaprio walked her down the aisle. 

Hello writes that the "Inception" star also provided massive support when Winslet's mum died of ovarian cancer. Reportedly, the pair did something amazing in her memory – they auctioned off a dinner with "Jack and Rose" and raised $1.35 million. The besties then put the money towards another woman's cancer struggle, and she went on to survive.

In 2016, when DiCaprio finally won an Oscar for his performance in "The Revenant," Winslet was one of the first to congratulate him. She told Vanity Fair that she couldn't boycott the ceremony as "I feel very strongly that it may possibly be Leo's year. He is my closest friend in the world and I just couldn't imagine not being there to support him."