Leonardo DiCaprio played Jack Dawson.
This was him then; he was only 22 when the movie was released:
And here he is at 47:
The last big movie he was in was 2021's Don't Look Up.
Kate Winslet played Rose.
This was her then; she was 22 when Titanic came out:
And here she is now at 47:
She's in the new Avatar movie.
Alexandrea Owens-Sarno played the little girl Cora.
Here she was then:
And here she is now:
She's still acting.
Jason Barry played Tommy Ryan.
This was him then:
And here he is now:
His IG bio says he's an actor, writer, and director.
Ewan Stewart played First Officer William Murdoch.
This was him then:
And here's the most recent picture I could find of him:
He was in a play called The Royale in 2015.
Suzy Amis played Lizzy Calvert who was Rose's granddaughter.
This was her then:
And here she is now:
She quit acting in 1998 and married James Cameron in 2000.
Jonathan Hyde played J. Bruce Ismay.
This was him then:
And here he is now:
He played Claudius in a production of Hamlet.