Backline duo commits to Quins
Samoan international Stanley, 27, joined Quins from the Highlanders last year but injury restricted him to just eight appearances last season. While Walker, 23, has scored 23 tries in 52 appearances for the Premiership club since making his senior debut in 2011.
Harlequins have not disclosed the length of the duo's new deals at the club.
"I am absolutely delighted that both Charlie and Winston have seen fit to extend their contracts," said Harlequins Director of Rugby John Kingston.
"I have no doubt that these two talented and valued backs have major roles to play going forward."
Walker has graduated from Harlequins Academy and has been with the club since joining from the Leicester Tigers Academy in 2010.
"The decision to extend my time at Quins was quick and easy as I love everything about this club," Walker said.
"I'm really excited to be working with the new management and I hope to be an integral part of the team in the years to come.'
However, Stanley made his debut for the Quins against Calvisano in 2015, his appearances last season were restricted due to a hamstring injury sustained against Wasps in February of this year.
He returned from that injury in May, earlier than expected.
"I am delighted to have committed to Harlequins," Stanley said.
"The club is full of good people and it is very passionately supported. I have thoroughly enjoyed my time here and I am excited by the opportunity to contribute to the future success of this club."
