Knightley's response comes amid producer Jerry Bruckheimer's comments about continuing the 'Pirates' franchise.
The Pirates of the Caribbean ship seems to have sailed for Keira Knightley! ET spoke to Knightley at the premiere of her new Hulu original movie, Boston Stranger -- out Friday -- where she explained why she wouldn't make a return to the beloved Disney franchise.
"What about Elizabeth Swan?" Knightley joked when asked if she would re-join the crew, given Pirates producer, Jerry Bruckheimer's recent comments about bringing back the saga, potentially with Johnny Depp's Jack Sparrow at the helm. "I mean, she sailed away so nicely. She sailed away in brilliant style."
As for what she remembers about the franchise's first film which is celebrating its 20th anniversary this year, Knightly said, not "very much."
"It sort of launched me out of a rocket, really, as far as my career went," she shared. "That year was Bend It Like Beckham, Love Actually and Pirates of the Caribbean."
She continued, "So, I'm being asked about all three. Unfortunately, I was 16 and 17. so I don't really remember very much of it, but yes, it certainly was a very big year for me. "
Knightly's response comes just days after Bruckheimer told ET at the Oscars Sunday that he "would love" to bring Depp back for the Pirates sequel currently in the works.
"We'll see. I would love it. I would love to have him in the movie. That's all I can tell you," Bruckheimer said.
As for an update on the franchise's upcoming sixth film, the Academy Award-nominated producer said, "We're all working on it. We'll see how it comes out."
He continued, "But we're all very excited. I think we're gonna have a great screenplay, and we're getting close."
As for who will be the leading lady in the next Pirates film, and whether or not Depp will return, that all remains to be seen. It was confirmed last year, though, that a female-led Pirates of the Caribbean sequel series, starring Margot Robbie, has since been made to walk the plank.
Pirates rumors aside, Knightley's busy in a female-led drama of her own with Boston Strangler, telling ET that it's rare to see a true crime story told through the "female gaze."
"I just thought it was really interesting, 'cause there's so many true crime things, people love them so much, but it's very rare to find one through a female gaze," She explained. "And the fact that this is such a famous case, where largely the two women who were -- I mean, who actually named the killer himself, had been sort of forgotten from it. I thought that was really interesting, and a sort of opportunity to highlight their part in the story."
In the film, Knightley plays reporter, Loretta McLaughlin, who becomes the first person to connect a series of murders and break the story of the Boston Strangler. She and Jean Cole team up to challenge the sexism of the early 1960s and report on the city's most notorious serial killer.
Knightley applauded the women's ability to power through and have their voices heard, despite the challenges they faced at the time.
"I think it's really lovely to see women who are struggling so much with the sexism of the time, but also just powering through it and finding their own way and promoting their own voices," Knightley maintained.
Boston Strangler hits Hulu March 17.