But it nearly didn’t happen like that! Before Leo was signed up for the role of heroic Jack, Kate Winslet was screen-tested with other actors for his role, and one of those unfortunate draft versions has now been uncovered.
The clip shows Kate hard at work as Rose, trying to conjure up the chemistry with ‘Clueless’ star Jeremy Sisto as Jack.
As you can see, the results were less than convincing - something James Cameron and co evidently agreed - leaving the floor clear for Leonardo to team up with Kate and become the king of the world, making box office history in the process.
What of Jeremy Sisto? Well, he went on to appear in ‘Six Feet Under’, ‘Law and Order’, and was nominated for a Critics Choice Award for his role in TV sitcom ‘Suburgatory’.
And Kate and Leonardo went on to scoop Oscars for later roles in 'The Reader' and 'The Revenant' respectively, so everything turned out well for all involved.
Tap the first picture to open the slideshow: