Rachel McAdams is dating Taylor Kitsch

A source close to the 36-year-old Canadian beauty said: "It hasn't been long. But it's serious."

Another insider said: "They grew closer on set."

Taylor, 34, recently split from fitness instructor Jennifer Welch, but wasted no time asking Rachel out on a date.

The couple were first spotted enjoying a romantic dinner date at Osteria Mozza in West Hollywood, Los Angeles early last month.

A third source said: "I don't know if it's full-blown love yet, but they talk constantly. They're really into each other. She talks about him all the time!"

The 'Notebook' actress, who previously dated Ryan Gosling, was most recently linked to her 'Southpaw' co-star Jake Gyllenhaal.

But she previously admitted she tries to avoid falling in love on set.

She said: "A set may seem like a good place for romance, but I don't think it's very conducive; it's too distracting. Every relationship I've had with a co-worker comes after the fact."