The 23-year-old joined Palace from American University side West Virginia in January 2022 and made 10 Women’s Championship appearances in her maiden half-season with the Eagles.
An ACL injury sadly restricted Sibley to just five league appearances in 2022/23, however, with the defender successfully undergoing surgery last winter.
Having continued her rehabilitation with Palace beyond the expiration of her contract this summer, Sibley’s return to fitness and impact in training have seen her awarded a new deal with the club.
Palace head coach Laura Kaminski said: “We’re delighted that Issy has continued to recover so well from such a challenging injury.
“It is testament to the strength of her character and mindset that she has been awarded this new contract, and we look forward to seeing her back out on the pitch – at the right time for her and the team – as we look to build on our results so far this season.”
Sibley said: ”I'm ecstatic to be staying with Palace. There are big ambitions in the team and at the club itself, so I'm very happy to be signing on with the club for a bit longer."
Everyone at Crystal Palace would like to congratulate Isabella on her new contract.
Crystal Palace Women's next fixture is against Blackburn Rovers Women on Sunday, 8th October at Ewood Park.
Tickets for Palace's next two home Women's Championship fixtures – against London City Lionesses on Sunday, 15th October (14:00 BST) and Lewes on Sunday, 12th November (14:00 GMT) – are now on sale.