"With some rest she will be fine," her publicist, Stephen Huvane, said in an e-mail.
Huvane would not disclose how the actress fractured her knee or when.
Pictures of Paltrow wearing flip-flops and walking with crutches were posted on the Web site X17 on Friday. The actress had bandages on her knee.
Paltrow won an Oscar in 1998 for her role in the film "Shakespeare In Love."
She has two children with Coldplay lead singer Chris Martin.
By Amy Bonawitz