The British actor previously admitted there hasnâ€™t been a repeat showing of the film in her household, saying itâ€™s â€œvery odd watching films that youâ€™re inâ€.
It doesnâ€™t sound like thatâ€™s going to change anytime soon, but in a new interview, Keira says she definitely knows who Juliet ends up with.
In the film, Mark (Andrew Lincoln) has a crush on Juliet, who is his best friend Peterâ€™s (Chiwetel Ejiofor) wife.
He reveals this to her in one of the filmâ€™s most famous scenes, which sees him showing up at Julietâ€™s home on Christmas Eve with a series of cue cards expressing his devotion to her.
She responds by giving him a quick kiss before returning to her husband inside
So who does Juliet end up with?
â€œNo, I have not watched the film again. Yes, I know that I stay with my husband,â€ Keira told EW with a laugh.
Although fans have speculated about Juliet and Mark over the years, writer-director Richard Curtis revealed that she did stay with her husband in the 15-minute mini-sequel, Red Nose Day Actually, which aired as part of the 2017 Red Nose Day fundraising campaign.
Mark, meanwhile, is revealed to have married his longtime celebrity crush, Kate Moss.
Andrew Lincoln has previously spoken about his characterâ€™s divisive approach to letting Juliet know his true feelings.
â€œMy big scene with the cards in the doorway felt so easy. I just had to hold cards and be in love with Keira Knightley,â€ he said.
â€œItâ€™s why cinema is so pure. Itâ€™s like a silent film. That was why I totally got it, even on the script level. But I kept saying to Richard, â€˜Are you sure Iâ€™m not going to come off as a creepy stalker?â€™â€
Last year, Martine McCutcheon â€“ who played Downing Street staff member Natalie in the film â€“ revealed she didnâ€™t think the cue card scene was â€œcreepy at allâ€.
â€œI think people do crazy things when they are in love with people,â€ she told Digital Spy.
â€œHe had his moment where he thought â€˜enough now, Iâ€™ve told her how I feel, I love my friend too but I had to get it off my chest in the right wayâ€™.
â€œSheâ€™d already seen the video, and I think it was his way of making things explained and comfortable.â€