She is an English former football forward who spent three spells with FA WSL club Arsenal Ladies. A product of the American college soccer system, Smith broke records with Seton Hall University then played professionally with Women's United Soccer Association (WUSA) franchise Philadelphia Charge. After returning to Arsenal for a period which included a 2007 UEFA Women's Cup win, Smith was tempted back to America with another professional contract, this time with Boston Breakers in Women's Professional Soccer (WPS). She accumulated 117 caps for the England women's national football team since making her debut in 1995. Despite being hit by serious injury during her career, Smith is England's record goalscorer with 46 goals. She played for Great Britain at the 2012 London OlympicsSmith debuted for the England national team on 1 November 1995, three days after turning 17. The 1–1 draw against ;Italy was played at Roker Park and Smith won Player of the Match from her position on the left wing. She had been unable to accept a call-up to England's 1995 FIFA Women's World Cup squad that summer due to sitting her exams. Her first international goal came on the occasion of her second cap, against Croatia on 19 November 1995. Smith scored a stoppage-time penalty in England's 5–0 win at the Valley. During the following years, the English Football Association (FA) complained to FIFA when Smith's American college team refused to release her for national team duty.When healthy, Smith has generally been considered one of the world's top female players; former United States head coach April Heinrichs asserted that Smith would be an automatic choice for the United States Women's National Team if she had been eligible, and Vera Pauw, the Dutch coach, called Kelly "the best player in the World" after she scored a hat-trick against the Netherlands in a 2007 FIFA Women's World Cup qualifier. During the 2011 World Cup, Mia Hamm said of Smith: "I remember the first time I saw Kelly play. She'd just graduated from Seton Hall. She's incredibly technical, with great speed of thought and play. Her touch is different class – everything's clean, everything's with a purpose. The pace of her passes is always perfect and she can score at will too." Smith's former England teammate and later coach, Hope Powell, went further than Hamm: "Kelly is one of those players who come along only once or twice in a lifetime. In the men's game you'd think of Diego Maradona or Messi, players with a unique talent, and that’s what Kelly has."Smith has competed in the 2001, 2005, and 2009 editions of the UEFA Women's Championship, as well as the 2007 and 2011 FIFA Women's World Cup with England. She also played in the 2007 China Cup against the United States, and China where she was named the player of the tournament. Smith was voted third in the 2009 FIFA Women's World Player of the Year, fourth in 2007 and fifth in 2006 and 2008.Smith reportedly became England's all-time record goalscorer in September 2010, when she scored her 41st international goal against Switzerland and surpassed the previous record of 40 goals held by Karen Walker.In 2011, Smith competed in the FIFA World Cup, where she scored from the spot in England's quarterfinal match with France, to give England a 1–0 lead in the penalty shootout (England would go on to lose the shootout 4–3). Smith, hindered by an achilles injury, was dissatisfied with her own performances at the tournament: "I have to acknowledge that I didn't play well and I have to live with that." She returned to the England squad for a UEFA Women's Euro 2013 qualifying tie with Serbia after missing the first three matches of the campaign. On 3 February 2015, Smith announced her retirement from international duty.