The 37-year-old midfielder - who currently plays for Reading in the Women’s Super League (WSL) - announced via social media on Monday that she would be calling time on an illustrious playing career that has lasted for more than two decades at the end of the 2020/21 campaign.
“After much consideration and despite offers to remain within the game, I have made the difficult decision to retire from professional football at the end of the season,” Williams said on Twitter.
“It has been a pleasure and a privilege to have had a career of more than 20 years within the women’s game.”
Williams went on to earn 172 caps - scoring 40 goals - for England after making her international debut as a 17-year-old in 2001 and was part of the team that finished as runners-up at the 2009 European Championship and in third place at the 2015 World Cup, scoring an extra-time winner in the third-place play-off against Germany.
She also helped the Lionesses to reach the semi-finals at Euro 2017, but was not selected by manager Phil Neville in the squad for the 2019 World Cup in France.
She made her 100th England appearance at the 2012 Cyprus Cup, winning that competition three times in 2009, 2013 and 2015.
Former FA skills coach Williams also played for Great Britain at the 2012 Olympic Games in London.
After beginning her club career at Chelsea, Williams represented Charlton Athletic before an eight-year stint at Everton - which included an FA Women’s Cup triumph in 2010 - was followed by a spell with Merseyside rivals Liverpool, where she won back-to-back WSL titles in 2013 and 2014.
Williams also lifted the FA Cup with Arsenal in 2016 and joined current club Reading in 2017.
She was awarded an MBE in the Queen’s New Year Honours List in 2016 and has worked as an ambassador for the Homeless FA after revealing that she was homeless herself for the first six years of her football career.