Ffion Davies was born on January 18, 1995, in Wales, United Kingdom. From a young age, she demonstrated a strong affinity for physical activities, initially participating in rugby before discovering judo at age 8. Davies quickly excelled in judo, capturing Welsh and British Open junior titles and earning a spot on the Welsh junior national squad. She achieved her judo black belt during her teenage years. Despite these early accomplishments, Davies grappled with self-confidence issues and struggled to form meaningful connections within the judo community, leading her to temporarily step away from competitive sports during adolescence.

In 2013, Davies transitioned into mixed martial arts (MMA), training alongside UFC fighter Brett Johns in Wales. She rapidly found success in amateur MMA, compiling an undefeated 4-0 record with all victories via first-round submission. Through MMA, Davies encountered Brazilian Jiu-Jitsu, appreciating its similarities to judo but enjoying its fewer restrictions and greater technical freedom. Initially training under Swansea-based instructor Chris Rees, Wales' first BJJ black belt, Davies earned her blue belt and soon shifted her competitive focus exclusively to Brazilian Jiu-Jitsu, driven by her passion for the art.

Davies quickly ascended the competitive ranks, achieving groundbreaking milestones for British and European grapplers. She became the first British (Welsh) black belt World Champion in Brazilian Jiu-Jitsu, capturing the IBJJF World Championship no-gi title in 2018 and the gi division in 2019. In 2022, Davies made history as the first-ever ADCC champion from the U.K., winning gold in the -60kg division at the 2022 ADCC World Championship. She also became the first European athlete to win the Brazilian Nationals in 2019 and the lightest competitor ever to claim the IBJJF European Championship absolute title. In December 2023, Davies achieved another historic feat, becoming the first lightweight competitor to win double gold at the 2023 IBJJF World No-Gi Championship, submitting Heather Raftery in the absolute final.

Throughout her career, Davies has consistently sought out high-level training environments internationally. After her initial training under Chris Rees, she relocated to Ireland to train under Darragh O’Conaill at East Coast Jiu-Jitsu, where she received her black belt in November 2018. In 2021, Davies spent several months at Essential Jiu-Jitsu in New York, training under JT Torres. She credits this experience—particularly the emphasis on positional sparring and training with elite partners—for significantly elevating her competitive performance. Davies emphasizes enjoyment and personal growth over competition results, a philosophy that has positively influenced her mental health and overall athletic development.

Davies is renowned for her aggressive, dynamic competition style, heavily influenced by her judo background. Her matches frequently showcase precise foot sweeps and powerful throws, exemplified by her memorable uchi-mata attempt against Beatriz Mesquita at the 2019 ADCC World Championship. Davies consistently pursues submissions rather than stalling for points, reflecting her MMA experience and attack-oriented mindset. Her resilience and determination are evident, notably competing through injuries and adversity—including a mugging incident in Brazil the day before the 2019 IBJJF World Championship, where she still secured double medals.

As one of Brazilian Jiu-Jitsu's most prominent female athletes, Davies actively advocates for women's participation and growth within the sport. She regularly leads women-only seminars and camps, notably headlining Girls in Gis events across Europe. In 2023, Davies took a significant step into coaching by promoting Rosa Walsh to black belt, making Walsh Ireland’s first female BJJ black belt. Davies also mentors younger athletes such as Jasmine Hearn, providing guidance on competition mindset and training routines. Openly discussing mental health, anxiety, and burnout, Davies encourages young competitors to prioritize enjoyment and mental well-being, sharing her experiences to inspire and support others.

Davies' competitive achievements have significantly elevated the popularity and mainstream media coverage of Brazilian Jiu-Jitsu in Wales. Her historic ADCC victory in 2022 was celebrated as a national sporting milestone, bringing unprecedented attention to the sport within the region. As a role model for European grapplers, Davies demonstrates that athletes from outside traditional BJJ powerhouses like Brazil and the USA can achieve the highest levels of success. She continues to advocate for improved infrastructure and increased opportunities for women in Brazilian Jiu-Jitsu throughout the U.K. and Ireland, solidifying her legacy as a trailblazer and influential figure within the global BJJ community.