Thompson is a native of Banana Ground in Manchester Parish, Jamaica. Running for Christiana High School and later Manchester High School, Thompson was a good but not outstanding scholastic sprinter; her best result at the Jamaican Boys and Girls Championships came in 2009, when she placed fourth in the Class Two 100 metres in 12.01. In 2011, her final year at Manchester High, she was left off the track team for disciplinary reasons.
After high school, she was recruited to the University of Technology, Jamaica by Paul Francis, brother of MVP Track Club head coach Stephen Francis. With MVP coaching, Thompson's times started improving steadily. In 2013, she clocked a season best of 11.41 at the Gibson Relays and placed second behind Carrie Russell at the Jamaican Intercollegiate Championships; at the 2013 Central American and Caribbean Championships in Morelia she won gold in the 4 × 100 metres relay, running the first leg on the Jamaican team as it won in 43.58. In 2014 Thompson won her first intercollegiate title, placed fifth in 11.26 at the national championships and had a season best of 11.17. She represented Jamaica at the 2014 Commonwealth Games in Glasgow, running in the 4 × 100 m relay heats; Jamaica won their heat in 42.44, and went on to win gold in the final with Thompson not in the line-up.
Thompson made her international breakthrough in 2015. She repeated as Jamaican intercollegiate champion in March and broke 11 seconds for the first time at the UTech Classic on 11 April, running a world-leading 10.92. She then ran 10.97 at the Jamaica International Invitational in Kingston, defeating a field that included Blessing Okagbare and Allyson Felix; the win confirmed her new status as one of the world's leading sprinters. At the Pre Classic in Eugene Thompson was narrowly beaten by English Gardner in the B-race as both were timed in 10.84; as of 27 July 2015, which was Thompson's personal best in the 100 m and ranked her 30th on the world all-time list.
Thompson was expected to run the 100 metres at the Jamaican National Championships, which doubled as trials for the 2015 World Championships in Beijing; however, her coach Stephen Francis pulled her from that event and instead had her concentrate on the 200 metres, in which she had set a personal best of 22.37 in May. The move generated controversy in Jamaica; Francis stated that Thompson was not ready to double, and that she had been prepared for the 200 m in which her main weakness, the start, would not play as large a role. Thompson won the national 200 m title in 22.51, qualifying for the World Championships.
At the London Grand Prix on 25 July 2015 Thompson won a non-Diamond League 200 m race in 22.10, defeating Americans Tori Bowie and Candyce McGrone; the time was her new personal best and broke Merlene Ottey's meeting record from 1991. At the 2015 World Championships held in Beijing, Thompson won the silver medal, behind Dafne Schippers. Thompson's time of 21.66 was faster than the previous championships record but 0.03 slower than Schippers.
In the 100 metres women's final in the 2016 Olympic Games in Rio de Janeiro she won the gold medal, ahead of Tori Bowie and the 2012 London Olympics winner and fellow country woman Shelly-Ann Fraser-Pryce.
In the 200 metre woman's final in the 2016 Olympic Games, Thompson won the gold medal, ahead of Dafne Schippers of the Netherlands.
She is the first female Jamaican sprinter to win the 100 metres and 200 metres at the Olympic Games.
Elaine Thompson became the first woman to win a gold medal in both the 100m and 200m, at the same Olympics (Rio 2016), since Florence Griffith Joyner accomplished the feat at the Seoul Olympics, in 1988.100 meters
2017: 10.71 (24 June 2017)