Raducanu was born in Toronto to a Chinese mother and Romanian father, and she was raised in London. Raducanu made her WTA Tour debut in June 2021. As a wild card ranked outside the top 300 at Wimbledon, she reached the fourth round in her first major tournament. At the US Open two months later, Raducanu became the first qualifier in the Open Era to win a Grand Slam singles title, beating Leylah Fernandez in the final.
Emma Raducanu was born on 13 November 2002 in Toronto, Ontario, Canada. Her father came from Bucharest, Romania, while her mother originates from Shenyang, China. She recalled her parents "both came from very academic families... [in] communist countries education was kind of their only option". She and her family moved to England when she was two years old. Raducanu started playing tennis at the age of five. She attended Bickley Primary School followed by Newstead Wood School, a selective grammar school in Orpington, where she obtained an A* in mathematics and an A in economics in her A-Levels. As a child, she participated in various sports and activities, including basketball, golf, karting, motocross, skiing, horse riding, and ballet. She is a fan of Formula One.
Raducanu has attributed her mentality and ethics to her role models, tennis players Simona Halep and Li Na (who are from countries of her ancestry).
Raducanu won the ITF Chandigarh Lawn Tennis girls tournament at the beginning of 2018. In 2018 she won ITF grade-3 at Chandigarh and grade-2 junior tournament at New Delhi both in India. Raducanu defeated Diana Khodan of Ukraine in the final at Chandigarh, held at Chandigarh Lawn Tennis Association Stadium, where she won in straight sets.
Later that year, she reached the girls' singles quarterfinals at both the Wimbledon Championships and the US Open. At Wimbledon, Raducanu defeated Leylah Fernandez in the second round, a feat she would eventually repeat in the senior US Open final three years later.
Raducanu turned professional in 2018. She alternated between junior and professional tournaments during 2018 and 2019.
In 2019 Raducanu competed in the Solapur Open in Maharashtra. She reached the second round in the Solapur Open women's ITF $25K tennis tournament, retiring in the second round.
She won the ITF NECC-Deccan $25,000 tournament in Pune, India, in December 2019. In the final at Deccan Gymkhana club, she won against Naiktha Bains in three sets. Her semifinal and quarterfinal victories came in three sets. It was her best title victory before winning the 2021 US Open.
In 2020, many tennis events were cancelled due to the COVID-19 pandemic. Raducanu participated in exhibition matches and small tournaments in the United Kingdom. She won the LTA British Tour Masters title in December 2020. She also devoted time to her academic studies, preparing for her A-Levels (which she took in 2021).
Raducanu defeated Leylah Fernandez in two sets in what was the first all-teenage women's singles final since the 1999 US Open between Serena Williams and Martina Hingis. She won the title without dropping a set, the first woman to do so at the US Open since Williams in 2014. Raducanu was the first qualifier to win a Grand Slam tournament in the Open Era, and the first woman in the Open Era to win a major tournament on her second appearance. It also meant that she became just the second US Open debutante after Bianca Andreescu to win the tournament.
As a result of her US Open victory, Raducanu rose to No. 23 in the world rankings. She was the first British woman to win a Grand Slam singles title since Wade at Wimbledon in 1977, and the first British Grand Slam singles champion since Andy Murray at the 2016 Wimbledon Championships.
Raducanu is an aggressive baseliner. As her playing style is focused on offence, she typically hits a considerable number of winners; despite her aggressive playing style, Raducanu typically minimises unforced errors and focuses on rallying until she creates the opportunity to hit a winner. Raducanu excels at hitting the ball early on the rise, and is adept at redirecting power down the line, taking time away from her opponents; her signature shot is her backhand down-the-line. Her groundstrokes are typically hit very flat, with little topspin applied, allowing her to dictate play from the baseline. Raducanu's greatest strength is her two-handed backhand, which is hit with considerable depth, speed, and penetration; her backhand was described as "world-class" by former British No. 1 Anne Keothavong. Raducanu does have the ability to hit her backhand one-handed with slice, to break up the pace of rallies and disrupt her opponent's rhythm, however, she does not utilise this shot frequently.
Raducanu's forehand is also strong, and she is capable of hitting winners with this stroke, especially when redirecting power down-the-line; her forehand is more volatile than her backhand, however, and is targeted by players acquainted with her style of play. Raducanu possesses an aggressive serve, peaking at 110 mph (177 km/h), allowing her to serve multiple aces per match; this is aided by her consistent ball toss, and accurate serve positioning. Despite this, Raducanu's most effective serve is her wide, sliced serve, with which she can dominate play; she utilised this serve during the 2021 US Open final against Leylah Fernandez on her third championship point, serving an ace to close out the match. Raducanu's second serve is strong, typically being delivered at a higher speed than the WTA average, at 93 mph (150 km/h); however, her accuracy when delivering her second serve confounds opponents, and allows her to dictate play from a frequently defensive position.
One of Raducanu's major strengths is her aggressive return of serve; she typically neutralises strong first serves by returning the ball hard, close to the baseline, and down the middle, cutting off her opponent's angle, and setting herself up for an aggressive second shot. She also frequently punishes short second serves, and she hits many second-serve return winners in any given match. When playing defensively, Raducanu excels at absorbing, generating, and redirecting power both down-the-line and cross-court, allowing her to turn defence into offence effectively.
Further strengths include Raducanu's movement, speed, footwork, court coverage, anticipation, and sense of balance, allowing her to rally and defend effectively against aggressive opponents, and to induce unforced errors from such players. She also excels at intelligent point construction, approaching each point with tactical flexibility, making it difficult for opponents to read her game. Despite typically playing from the baseline, Raducanu is a capable net player, attacking short balls with powerful swinging volleys, and she is capable of finishing points at the net. Raducanu possesses an effective drop shot, and can utilise aggressive drop shot/lob combinations to win points when given the opportunity. Due to her aggressive groundstrokes, her highly athletic playing style, and her defensive capabilities, she has been compared to her sporting idols, Li Na and Simona Halep. Despite being comfortable on all surfaces, Raducanu has stated that she prefers hard courts, where she won her maiden Grand Slam title.