Powell’s re-signing follows the shock exit of England full-back and 2024 World Player of the Year Ellie Kildunne earlier this month.
“I’m pleased to be re-signing with Harlequins,” said Powell.
“I feel that as an individual and as a club we have so much more to achieve. Our core values and the style of rugby we want to play excites me.”
Head coach Ross Chisholm said Powell “has so much experience and talent in a number of positions”.
“She is elusive in attack and a real rock in defence,” said Chisholm.
“I feel Kayleigh has developed her game over the last few seasons and believe that this is the best place for her to continue to thrive and show how good a player she is.”
