[3] Boulter was born in Woodhouse Eaves, Leicestershire,[4][5] the second of two children to David and Susan (née Gartshore) and has an older brother, James.

[12][13][14] In May 2014, in Sharm El Sheikh, Boulter won her first senior singles title over fellow Briton Eden Silva.

[15] A month later, Boulter was given a wild card for Wimbledon qualifying, losing in the first round to Italian Alberta Brianti in a three-set match which lasted two-and-a-half hours.

[20] In July, Boulter received a wildcard into the $100k grass-court event in Southsea, England, where she reached the final and fell to Kirsten Flipkens.

[25] Her next tournament was the St. Petersburg Ladies' Trophy where she entered the main draw as a lucky loser and was defeated by Ekaterina Alexandrova in three sets.

[34] Having won an ITF tournament in February 2022, Boulter had to retire from the WTA event in Lyon in March due to a leg injury.

[35] Boulter missed the clay-court season, but returned at the Nottingham Open in June where she came through qualifying to defeat Tatjana Maria in the first round before losing to Ajla Tomljanović.

Granted a wildcard for the Birmingham Classic, she defeated Alison Riske (her first win against a top-40 ranked player)[36] and Caroline Garcia,[37] before losing to Simona Halep.

She received a special exempt entry into the next UK tournament in Birmingham, but lost in the first round to Zhu Lin in straight sets.

[49] At Wimbledon, she defeated Australian Daria Saville in the first round[50] and Bulgarian Viktoriya Tomova in the second,[51] before losing to Elena Rybakina in an under-one-hour match.

[59] She reached the second round of the Australian Open with a win over Yue Yuan[60] but lost to 12th sedd and eventual runner-up Zheng Qinwen.

[61] Boulter played the Linz Open where she defeated sixth seed Jasmine Paolini,[62] before losing to Anastasia Pavlyuchenkova in the second round.

[69] In the final, she defeated the sixth seeded Marta Kostyuk achieving her first win at this level and taking her ranking into the top 30.

[70][71] In April, Boulter helped Great Britain to a 3–1 win in an away tie against France to make it into the Billie Jean King Cup finals.

[72] Boulter retained her Nottingham Open title in June, beating Emma Raducanu in the semifinals, and then Karolína Plíšková in the final on the same day at the tournament which was heavily affected by bad weather.

[84] Seeded 31st, she defeated qualifier Aliaksandra Sasnovich in the first round at the US Open,[85] before losing her next match to Jéssica Bouzas Maneiro.

[88] At the final WTA 1000 event of the season, the Wuhan Open, Boulter lost in the first round to qualifier Lesia Tsurenko.

[91] Seeded ninth at the Pan Pacific Open, She defeated qualifier Priscilla Hon,[92] lucky loser Kyōka Okamura[93] and Bianca Andreescu[94][95] to reach the semifinals where she lost to wildcard Sofia Kenin.

[103][104] At the Billie Jean King Cup finals in Spain, Boulter defeated Laura Siegemund in straight sets to seal Great Britain's first round win over Germany.

[108] At the United Cup, Boulter defeated Nadia Podoroska and then partnered Charles Broom to overcome María Lourdes Carlé and Tomás Martín Etcheverry as Great Britain won their opening group match against Argentina.

[116][117] Only main-draw results in WTA Tour, Grand Slam tournaments, Billie Jean King Cup and Olympic Games are included in win–loss records.