Smith finished third in the 2009 FIFA World Player of the Year standings and has influenced countless people, both at home and around the globe.
Smith, who played professionally in the United States from 1999 to 2004 and again from 2009 to 2012, capped off her third spell with Arsenal Ladies with an FA Cup triumph in front of a record crowd at Wembley in May, describing it as "the most glorious way to complete my career".
"I started at the age of 8 playing on local boys' teams; I moved on to Watford Ladies; to Wembley Ladies; and then Arsenal Ladies. Along with the clubs I played for in the USA, I've gathered a treasure trove of lessons and memories."
Smith first played for England in 1995 and finished her international career 20 years later as the Lionesses' all-time leading goalscorer with 46 senior goals in 117 appearances.
She was not part of the England squad that finished third place at the 2015 World Cup having called time on her international career earlier that year, but had played in two previous World Cups and four European Championships, as well as the 2012 Olympics on home soil.
Smith particularly thanked Arsenal Ladies, with whom she'll now take up a full-time coaching position. She describes it as a "fantastic opportunity to pay back the club I love, and to nurture the next generation of female football talent".
Current England captain Steph Houghton told the FA's official website, "Kelly is simply one of the best players in the world and I think the greatest-ever England player.
"I am honoured to have played in the same team as her."
To continue the discussion on Twitter follow @jamiespencer155