Sally Jane Janet Gunnell, OBE, DL (born 29 July 1966) is a British former track-and-field athlete, who won the 1992 Olympic gold medal in the 400 metres hurdles. During a 24-month period between 1992 and 1994, Gunnell won every international event open to her, claiming Olympic Games, World Championship, European Championship, Commonwealth Games, Goodwill Games, IAAF World Cup and European Cup golds in the event, and breaking the British, European and World records in it. She is the only female British athlete to have won all four 'majors'; Olympic, World, European and Commonwealth titles, and was the first female 400 metres hurdler in history to win the Olympic and World titles and break the world record. Her former world record time of 52.74 secs in 1993 is still the current British record. She was named World and European Female Athlete of the Year in 1993, and was made an MBE in 1993 and an OBE in 1998.

Gunnell was born in Chigwell, Essex, England to Les and Rosemary Gunnell, and grew up on the family's three-hundred-acre farm and attended the local primary and West Hatch High schools in Chigwell.

Gunnell started out in athletics with the Essex Ladies club as an accomplished long jumper and heptathlete, before specialising in hurdling. In 1984, she narrowly missed Olympic selection at both heptathlon, with a score of 5680 points and in the 100 metres hurdles, where she set a UK junior record of 13.30 secs.

In 1986, having won the AAAs and UK titles, Gunnell won the Commonwealth Games gold medal in the 100 metres hurdles in Edinburgh, ahead of Wendy Jeal and 1984 Olympic heptathlon champion Glynis Nunn. She would remain the UK number one in the event over the next four seasons and reach the semi-finals at the 1987 World Championships and 1988 Olympics in the event.

Gunnell first attempted the 400 m hurdles event in 1987, with a 59.9 clocking. In 1988, in her first full season at the event, she would reach the Olympic final in Seoul. At the Olympic trials in Birmingham, she broke the UK record with 55.40. In Seoul she would improve this twice, first to 54.48 in the semis then to 54.03, to finish fifth in the final. This would remain her best time in the event for three years.

In 1989, Gunnell won the European Indoor title at 400 metres. Outdoors, she finished second in the 400 m hurdles at the European Cup behind East Germany's Petra Krug, but ahead of Olympic silver medallist Tatyana Ledovskaya. In September at the World Cup, she was third behind Sandra Farmer-Patrick of the US and Ledovsakya, but this time ahead of Krug. In January 1990, she defeated 1988 Olympic champion Debbie Flintoff-King to win the Commonwealth title in Auckland. The 1990 summer season however was disappointing, when she only finished sixth at the European Championships.

Gunnell entered into the best phase of her career in 1991, improving her own three-year-old UK record three times. In Monaco she ran 53.78, in Zurich she ran 53.62, then at the World Championships in Tokyo, she won the silver medal behind Ledovskaya with 53.16, the then third fastest time of all-time. Ledovskaya won with 53.11.

Gunnell won the 400 m hurdles at the 1992 Olympic Games in Barcelona, running 53.23 to defeat Sandra Farmer-Patrick. She also anchored the British 4 × 400 m quartet to a bronze medal. In 1993, she reached her peak, when she set the world record in the 400 hurdles to win gold in the World Championships in Stuttgart, winning in 52.74, narrowly ahead of Farmer-Patrick who ran 52.79, also inside the old record.