Alfred was born in the south
Castries community of Ciceron. Her father died when she was 12 years old. She attended
Leon Hess Comprehensive Secondary School in Saint Lucia (2013–2015) and
St. Catherine High School in Jamaica (2015–2018). She then pursued a bachelor's degree in Youth & Community Studies at the
University of Texas in the United States, combining academic studies and athletics. Alfred was a Central American and Caribbean U15 champion in 2015. Both that year and in 2017, she was recognised as Saint Lucia’s Junior Sportswoman of the Year. As a junior athlete, she was the
Commonwealth Youth Games 100 m champion in 2017, when the Games were held in
Nassau, Bahamas. She also captured silver in the
2018 Youth Olympic Games in
Buenos Aires, Argentina behind Nigeria’s
Rosemary Chukwuma.
2022 In 2022, Alfred had the all-time best NCAA performance in the 60 m at the
NCAA Division I Indoor Championships, running a fast 7.04 s in the heats. Then at the age of 21, she became one of the top 30 fastest women ever. Her run of 10.81 s (+1.7 m/s) in preliminaries of the women’s 100 m at the
Big 12 Conference Championships in
Lubbock, Texas on 14 May was a Saint Lucia national and championship record. It also marked her as the fastest woman ever from the
Organisation of Eastern Caribbean States. At the time, only six Caribbean women had ever run faster, and in the
NACAC region 17. The same month, she ran a wind-aided 10.80 s (+2.2 m/s) at the NCAA West Preliminary Round - the fastest time ever recorded under any conditions at the event. She won the
2022 NCAA Division I 100 m title in 11.02 s (+0.2 m/s) the day after her 21st birthday, completing an unbeaten collegiate season in that event. Running for the University of Texas, she became the first track athlete from Saint Lucia to win a Division I championship, and just the second Saint Lucian overall, after
high jumper
Jeanelle Scheper. She next went on to win her event at the inaugural
Caribbean Games in
Les Abymes, Guadeloupe in a time of 11.07 seconds (−0.2 m/s).
2023 On 25 February 2023, Alfred broke for the fourth time existing collegiate record and became the first woman in NCAA to ever dip under 7 seconds over the
60 metres with a time of 6.97 s at the Big 12 Indoor Championships in Lubbock, TX. Her time moved her up to eighth on the world all-time list. She also achieved the second-fastest all-time collegian mark in the 200 m of 22.26 s, behind only
Abby Steiner, to become the fourth-fastest woman of all time. On 11 March at the
NCAA Indoors in
Albuquerque, New Mexico (at altitude), Alfred improved at both these events with times of 6.94 s and 22.01 s respectively to take both titles and move to second on both respective world all-time lists. With "the greatest ever one day sprint double", Julien went on to compete in the women's 100m race at the
Istvan Gyulai Memorial, crossing the finish line with a time of 10.89 seconds, resulting in a victory over sprinter
Sha'Carri Richardson. After the end of the 2022–23 academic year, Alfred and
TCU football star
Max Duggan were named as
Big 12 Conference Athletes of the Year. Selected for the
2023 World Athletics Championships in
Budapest, she qualified for the final of the
100 metres and finished in fifth place. She also competed in the
200 metres at the Championships, and qualified for the finals and finished 4th.
2024: Olympic and World Indoor titles She won gold in the
women's 60 metres at the
2024 World Athletics Indoor Championships in
Glasgow, with a world leading time of 6.98 seconds. It was Saint Lucia's first ever World Athletics Indoor Championship medal. She finished second in the 100 metres at the
Prefontaine Classic in Eugene, Oregon in a time of 10.93 seconds. Alfred ran a lifetime best and equalled the stadium record in the women's 100 metres at the Racers Grand Prix in Kingston, Jamaica on 1 June 2024, running 10.78 seconds. On 12 July, she won the 100 metres in 10.85 seconds at the
Herculis Diamond League event in
Monaco. Alfred set a new national 200 m record of 21.86 seconds as she finished second behind
Gabrielle Thomas at the
Diamond League meeting in London on 20 July. She won gold in the
women's 100 metres at the
2024 Summer Olympics in
Paris with a national record time of 10.72 seconds, which earned Saint Lucia its first-ever Olympic medal. She also secured a silver medal in the
200 metres with a time of 22.08 seconds, finishing behind
Gabrielle Thomas. Following the Olympics, Alfred won the 100 m at the
Diamond League Final in
Brussels on 13 September, clocking 10.88 s. Alfred's victory in the Olympics sparked celebrations in Saint Lucia, with the government subsequently declaring 27 September 2024 as "Julien Alfred Day".
2025 Alfred won the 100 metres in a meeting record 10.75 seconds (+0.9 m/s) in Stockholm at the
2025 BAUHAUS-galan event, part of the
2025 Diamond League, on 15 June 2025. She ran 10.77 seconds to finish second to
Melissa Jefferson-Wooden in the 100 metres at the
2025 Prefontaine Classic on 5 July into a headwind (-1.5 m/s). She ran a 21.71, the joint-ninth fastest of all-time, to win the 200 m at the
2025 London Athletics Meet. She ran 10.76 seconds to win the 100 metres at the
Diamond League Final in Zurich on 28 August. In September 2025, she was a bronze medalist in the 100 metres at the
2025 World Championships in
Tokyo, Japan, running 10.84 seconds in the final.
2026 On 13 February, Alfred went into an early world lead with 6.99 seconds for the 60 metres at the Tyson Invitational in
Fayetteville, Arkansas, winning ahead of
Jacious Sears.{{cite web|url= https://world-track.org/2026/02/olympic-champion-julien-alfred-6-99-and-ncaa-champ-jordan-anthony-6-43-run-wls-at-tyson-invitational/#google_vignette ==Achievements==