The Muse frontman plans to take Marilyn and George - who are divorced - from their homes in Exeter, South West England to California for the festive season to enjoy a big family Celebration with Goldie Hawn and Kurt Russell, which will be the debut meeting for all of them.
A source told The Sun newspaper: "It will be the first meeting of both sets of parents. Things are getting serious between Kate and Matt and it's the obvious next step.
"Christmas is the only time they can get everyone together and the festive season is also the best time to do it.
"Matt's parents divorced when he was a teenager but they maintained a relationship. There's talk they could split the US trip between them."
Kate - who has a six-year-old son Ryder with ex-husband Chris Robinson - has previously introduced Matt to her famous mother, and he admitted beforehand he was "nervous" about meeting her.
He said: "I haven't met Goldie yet. We are meeting up next week. I'm quite nervous. You don't want her reading daft stories online - it's embarrassing when you meet someone's family for the first time."
The pair have been dating for around five months.