Broady has won nine singles and 13 doubles titles on the ITF tour in her career. On 7 March 2016, she reached her best singles ranking of world number 76. On 22 May 2017, she peaked at world number 56 in the doubles rankings.
Born in Stockport, Naomi Broady is a sister of the tennis player Liam Broady and has another brother, Calum and a sister Emma. She attended Priestnall School. Broady began playing tennis at the age of 7 and was the 2007 British under 18 girls' champion.
Broady competed on the junior ITF circuit from January 2004 until June 2008. She won one singles title in April 2006 at the Sutton ITF Junior Tournament and lost in the quarterfinals of four others, one of which was the 2008 Wimbledon girls' tournament, where she was beaten by Noppawan Lertcheewakarn of Thailand. She had a singles win-loss record of 21–13.
In junior doubles, Broady never won a title but reached the semifinals in one tournament and the quarterfinals in four others. In 2007, she and Tara Moore teamed up to compete in Wimbledon doubles, reaching the second round and Broady reached the same stage of Wimbledon doubles one year later partnering Jade Windley. Her final doubles win-loss record was 11–15 and her career-high combined ranking was world number 251 (achieved 7 July 2008).
Broady began playing on the adult ITF circuit in January 2005, but was unable to qualify for any of the five tournaments she entered. As a result, she finished the year without a world ranking.
She continued playing on the ITF circuit in 2006 but did not pass round two of any tournament until November, when she reached the quarterfinals of the $10,000 event in Sunderland, where she lost to Martina Pavelec. Her first ever year-end ranking was world number 1464.
Broady was again unable to progress past the second round of any tournament until August 2007 when she reached the quarterfinals of a $10,000 ITF event in Cumberland, West Hampstead, London, where Anna Smith beat her in three sets. She reached the semifinals of her final tournament in 2007, the Sunderland $10,000 ITF tournament, losing to Christina Wheeler. Her 2007 year-end worldwide ranking was world number 713.
In September 2007, Broady and fellow British competitor, David Rice, were both suspended by the LTA for "unprofessional behaviour" and "lack of discipline" due to pictures posted on the social networking website Bebo. The pictures and various comments made on them were deemed to be supportive of a lifestyle of drinking and partying, and as such, both players had resources such as funding and coaching withdrawn. Their pages on Bebo were later shut down. Brendan Gallagher of The Daily Telegraph later commented that the photos were "comparatively tame" and "not the cleverest move for a wannabe tennis star but hardly scandalous behaviour for a 17-year-old."
A more promising start to 2008 saw Broady reach the semifinals of her first $10,000 ITF event of the year in Sunderland. She was beaten by Johanna Larsson, 4–6, 2–6. In February she reached the quarterfinals in Portimão, before losing to Russian Nina Bratchikova. She made her debut on the WTA tour in June at the tier III DFS Classic qualifying tournament. She beat Andreja Klepač in the opening round before losing a hard-fought contest with Margit Rüütel in the second round. Her next tournament was another first for Broady: her first Grand Slam appearance in the qualifying draw of Wimbledon. She was beaten by Rika Fujiwara in the opening round. Following this she spent the rest of the season on the ITF circuit and reached three more quarterfinals, in Felixstowe ($25,000), Cumberland ($10,000) and Traralgon ($25,000). Her end-of-year ranking was world number 444.
Broady reached the quarterfinals of the $10,000 ITF event in Glasgow in January. She won her first adult title later that month in Grenoble, France. She was unseeded in this event but beat the number five seed, Varvara Galanina, in the quarterfinals and the number one seed, Youlia Fedossova, in the final. She did not drop a set throughout the tournament. In March she reached the quarterfinals of another ITF tournament; this one in Bath. Her performance in this event moved her into the top 400 for the first time in her career. In June, she qualified for her first WTA main draw, at the Aegon Classic in Birmingham. She held a match point against Alla Kudryavtseva before going down during a rain delayed match which was held over two days. She was defeated at the Aegon International in Eastbourne by Katie O'Brien and in the second round of qualifying at Wimbledon. She got injured and didn't play again until a $25,000 event in Mexico. She won the tournament to cap off the best week in her career. The week after she won a $10,000 event in Cuba.
Following a successful early half to the season, which included tournament wins in Sharm el-Sheikh, Namangan, and Fukuoka, it was announced that Broady would receive a wildcard into the main draw of Wimbledon. She recorded her first ever Grand Slam victory at the tournament, coming from a set down to defeat world number 92 Tímea Babos of Hungary. Her run was ended in the second round, losing to former world number 1 Caroline Wozniacki in straight sets. However, partnering Neal Skupski, she reached the quarterfinals in mixed doubles.
The start of Broady's season in 2015 was lacklustre, with only a few semifinal-appearances at ITF events. She did however achieve her first win on clay since 2011 in qualifying for the French Open, but lost in the secound qualifying round to Anastasia Rodionova. Her grass court season started well, reaching the semifinals of Aegon Surbiton Trophy and achieving her first win of the season over a top-100 player by defeating Ajla Tomljanović at the Birmingham Classic in round one before losing to Simona Halep in the next round. Broady also failed to defend her second-round points at Wimbledon, losing in straight sets to Mariana Duque.
Broady's season picked up however during on the American hardcourts. She qualified for the main draw of the 2015 Citi Open. There she defeated Jarmila Gajdošová in three sets and achieved her first win in the main draw of a WTA event outside of a British grass event. However, she lost to Ekaterina Makarova in her next match. She then won her first title of the season at a $25,000 ITF event in Landisville, where she defeated American player Robin Anderson in the final.
Broady attempted to qualify for the 2015 US Open, but lost in the final qualifying round to Anett Kontaveit. She next entered the 2015 Coupe Banque Nationale where she again lost in the final qualifying round but received a lucky loser entrance into the main draw. There she fought her way to her first semifinal of a WTA event, before ultimately losing to the young Latvian player Jeļena Ostapenko. It was during this period of wins during the US hardcourt season that it became clear that she had more confidence in her game, by using her big serve to make it difficult for her opponents to break her and playing aggressive in return games so she could break her opponents herself. For example, in her match against Jarmila Gajdošová at the Citi Open, she served 19 aces, which was the fourth highest number of aces in a match on the WTA tour in 2015.
Broady went on to reach the final of the 2015 Coleman Vision Tennis Championships, where she lost in an extremely close match Michaëlla Krajicek. She had two match points in the third set, but failed to close it out. She also hit 28 aces in this match, which was very close to breaking the record on the ITF circuit for a female player. After this loss, Broady reached a career high ranking of 116.
Broady began her 2016 season at the ASB Classic in Auckland, New Zealand. She entered the qualifying draw and defeated Laura Siegemund, Kateryna Kozlova, and Magdaléna Rybáriková for a spot in the main draw. In the first round, she recorded the biggest win of her career when she shocked number 2 seed Ana Ivanovic. Broady's second round contest with Latvian youngster Jeļena Ostapenko featured a controversial incident during a second-set tiebreak, when Ostapenko flung her racket in the direction of the back of the court, which subsequently hit a ball boy. Although the ballboy wasn't injured, Broady approached the chair umpire to enquire why Ostapenko had not been defaulted, on the grounds that the racket had been thrown in frustration and not in an accidental fashion. After hailing the WTA supervisor, Ostapenko was issued a code violation and would go on to lose to Broady in three sets. A cold post-match handshake was also met with further drama, as the two verbally berated each other in an argument while packing their bags. Broady went out in the next round when she lost out to American Sloane Stephens for a spot in the semifinals.
Having been eliminated in the opening round of qualifying at the Australian Open, Broady travelled to the United States to play the ITF events in Maui and Midland. Broady reached the semifinals in Hawaii before losing to top seed Christina McHale, but went two better by winning the $100,000 event in Midland, beating US youngster Robin Anderson in the final. Broady broke into the world's top 100 for the first time following these results.
Broady's next event was the qualifying of the high-value WTA Premier 5 event in Doha. She won her opening match, but then lost in final qualifying to Elena Vesnina. From here Broady moved on to Kuala Lumpur. She recorded wins over Klára Koukalová, Yang Zhaoxuan and former Wimbledon finalist Sabine Lisicki to reach her second WTA semifinal, exiting at that stage to another former Wimbledon runner-up, Eugenie Bouchard. This run lifted Broady to a new career high ranking of 76.
Competing in the ITF 2017 Dow Tennis Classic in February, Broady reached the singles final before losing in three sets to Tatjana Maria. In May in the 2017 Empire Slovak Open, Broady, partnered by Heather Watson, won the doubles competition on clay in two sets bringing Broady's doubles ranking to a new high of 56.
Broady's big serve is the stand out feature of her game. Her tactic is to dominate opponents with her serve, making it impossible for them to break her, and then to try to get a break herself. Off the ground she uses a one-handed backhand which can be very powerful but also breaks down easily. During rallies, Naomi hits powerful flat groundstrokes off both wings. She can also hit slice shots when on the defensive. She will often try to approach the net and volley to avoid long rallies.