Leonardo DiCaprio celebrates girlfriend Camila Morrone's 23rd birthday with yacht party

Camila Morrone and Leonardo DiCaprio started dating in December 2017. Photos / Getty Images

Leonardo DiCaprio celebrated Camila Morrone's 23rd birthday with a star-studded yacht party.

The 45-year-old actor and his girlfriend were joined by the likes of Nina Dobrev, Kevin Connolly, Lukas Haas and Olympic snowboarder Shaun White on board the 43 metre Leight Star Super Yacht for the daytime event in Los Angeles.

According to Page Six, Leonardo was one of the only people in attendance to wear a protective face mask, while the group wore cowboy hats and Western attire, suggesting a cowboy theme for the celebration.

The vessel sailed out towards Malibu from the Marina Del Rey at around 11am, before returning to shore at 4.30pm.

Leonardo and Camila have been dating for over two years but largely keep their relationship out of the spotlight, though they sat next to one another on the front row at the Academy Awards earlier this year.

However, the 'Once Upon a Time in Hollywood' actor didn't walk the red carpet at the event with the brunette beauty.

View this post on Instagram

☮️ ✌🏻

A post shared by Camila Morrone (@camilamorrone) on Jul 2, 2019 at 3:35pm PDT

The 'Mickey and the Bear' actress previously insisted she isn't bothered about the 23-year age gap between herself and Leonardo.

She said: "There's so many relationships in Hollywood -- and in the history of the world -- where people have large age gaps.

"I just think anyone should be able to date who they want to date.' "

Last year a Reddit user shared a graph they made outlining Leonardo DiCaprio's dating history, headlined "Leonardo DiCaprio Refuses to Date a Woman Over 25". Photo / Supplied

However, Camila admitted it is "frustrating" that her relationship overshadows her work, but she's hoping that will change soon.

She said: "I think more and more now that people are seeing the film, I'm slowly getting an identity outside of that.

"Which is frustrating, because I feel like there should always be an identity besides who you're dating.

"I understand the association, but I'm confident that will continue to slip away and be less of a conversation."