Kelly Jayne Smith MBE (born 29 October 1978) is an English former football forward who spent three spells with FA WSL club Arsenal. After moving to the United States, 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 national team after making her debut in 1995. Despite being hit by serious injury during her career, Smith is England's second-highest goalscorer with 46 goals. She played for Great Britain at the 2012 London Olympics. Smith was renowned for her speed, ball control and quickness in which she developed into a potent centre forward. She is considered by many who played with and against her to be one of the greatest ever players to come out of England, as well as one of the greatest players of all time.

While growing up in the Garston area of Watford, Smith regularly played football on boys' teams until, at the age of seven, she was kicked out of Garston Boys Club – despite being the top goalscorer – when the parents of her male opponents complained. After continuing at Pinner Girls, a team formed by Smith's father, she developed her skills at Wembley Ladies and made her senior debut in the 1994–95 season. In August 1995, Pete Davies wrote in The Independent that the "lethally quick, bountifully gifted" Smith was: "the outstanding prospect in the women's game today." After moving to Arsenal Ladies during 1996–97, she scored two goals and assisted on the third in a 3–0 win over Liverpool which secured the Premier League title that season. She spent that year at West Herts College, but transferred to Seton Hall University in the United States in 1997.

Smith enrolled at Seton Hall as a student-athlete. She played for the Seton Hall Pirates from 1997 through 1999. In her first year at Seton Hall in 1997, Smith set scoring records for the Big East Conference and became the first athlete in any sport to be the conference's (Offensive) Player of the Year and Newcomer of the Year in the same season. In the following two seasons, she was the leading scorer not only in the Big East, but in the whole of NCAA Division I, and was named Big East Offensive Player of the Year in both years. At the end of her university career, the school retired her number 6 shirt, she became the first Seton Hall athlete in any sport other than basketball to have a number retired. In her three years at Seton Hall, she set school records with 76 goals and 174 points while playing in just 51 matches.

At the culmination of her studies, Smith remained in the United States, remarking: "women's football in England is a joke." Smith's first professional club was New Jersey Lady Stallions of W-League, for which she played on from 1999 to 2000. However, a new top-flight women's league was about to start in the United States and Smith stayed in the country to participate in the project.

The Women's United Soccer Association was formed in early 2000. Smith was drafted second overall in the 2001 WUSA Foreign Allocation Draft by Philadelphia Charge. Smith played all three seasons with Philadelphia and was named to the 2001 WUSA Global 11 All-Star Team. 2001 was her only full season in the league; in 2002, Smith missed most of the season after tearing her ACL in her right knee, and missed much of 2003 after re-injuring the same knee. Following the 2003 season, the WUSA ceased operations.

Smith decided to keep playing in the United States following the collapse of the WUSA. In 2004, she played for the New Jersey Wildcats in the W-League, but she was injured yet again, breaking her leg. She ended up appearing in eight games for the club (563 minutes) and tallied eight goals and six assists.

Smith returned to England and Arsenal in the autumn of 2004. She officially rejoined in 2005 after being treated at the Sporting Chance clinic. However, she was yet again hampered by injury, this time by a stress fracture in her foot. She returned to action at the end of the 2004–05 season, scoring a goal from 30 metres out against Charlton Athletic L.F.C. which clinched the league title for Arsenal.

In Arsenal's "Quadruple" winning season of 2006–07, Smith scored 30 goals in 34 games across the four competitions. However, she missed both legs of the 2006–07 UEFA Women's Cup final through suspension, after being sent off for giving the finger to opposition fans in the semi-final.