[6][7] Haddad Maia has a degree on Business Administration which she got from graduating online in the distance education format at the Estácio de Sá University.

In 2014, she was handed a wildcard at both the Rio Open and Brasil Tennis Cup main draws, losing in the first round of singles and doubles of both tournaments.

At Bogotá, Haddad Maia won her first WTA Tour doubles title with compatriot Paula Cristina Gonçalves, defeating Irina Falconi and Shelby Rogers in the final.

Having fallen to the 367th position in the rankings by 18 July 2016, Haddad Maia recovered almost 200 spots during the second half of 2016, finishing the year with two consecutive $50k titles in Scottsdale and Waco.

The following week, Haddad Maia had the best performance of her career at the $100k Open de Cagnes-sur-Mer, when she won the title without dropping a set, defeating Jil Teichmann in the final.

Also on clay, she reached the semifinals of the Bol Open, a WTA 125 event, losing to the eventual champion, Aleksandra Krunić.

Haddad Maia received her first direct acceptance at a Grand Slam main draw at Wimbledon, losing in the second round to Simona Halep.

[9] In the doubles competition, she reached the third round with Croatian partner Ana Konjuh, losing to Chan Hao-ching and Monica Niculescu.

She also reached the quarterfinals, as a qualifier, at the WTA Tour event in Acapulco in late February, losing to eventual champion Wang Yafan.

[12] On 23 July 2019, it was announced by the ITF that Haddad Maia had been issued an immediate provisional suspension, pending determination of the charge against her at a full hearing, after a positive test for metabolites of two Selective androgen receptor modulator substances.

The federation's report didn't release her from responsibilities, citing the case of fellow Brazilian tennis players Marcelo Demoliner, Thomaz Bellucci and Igor Marcondes, who had found themselves in a similar situation.

[18] In October, at the rescheduled Indian Wells Open, Haddad Maia lost in qualifying but was awarded a spot in the main draw following the withdrawal of 29th seed Nadia Podoroska.

[25][26] Haddad won her biggest singles title at the WTA 250 Nottingham Open,[27] while also winning the doubles tournament alongside Zhang Shuai.

[28] She followed this victory up with facing Zhang in the final of the Birmingham Classic where Haddad won her second singles title, when the Chinese retired in the first set.

[29] She joined Ons Jabeur, who won in Berlin less than an hour earlier, and Iga Świątek as players to win multiple WTA Tour titles in the season.

24 in singles at the start of the Canadian Open, she reached the final by defeating Martina Trevisan, Leylah Fernandez, Iga Świątek, and Belinda Bencic.

[38] In an unprecedented Brazilian final at the WTA 1000 level against Luisa Stefani and Storm Sanders, they ended runners-up in a tight result, with a score of 7–6, 6–7 and [10–8] in favour of Stefani/Sanders.

[45] She won her first WTA 1000 doubles title at Madrid with Victoria Azarenka, defeating Jessica Pegula and Coco Gauff[46] in a final that was followed by controversy as none of the participating players were allowed to make a speech on the podium during the awards ceremony.

[49] Haddad was close to qualifying for the semifinals, but in an extremely long match lasting 3 hours and 41 minutes, the longest of the season, she lost to Anhelina Kalinina.

[50] Still in the first set, Haddad felt an injury to her left leg, which ended up limiting her movement in decisive moments of the game.

In her first-round match, she slipped and felt a strong pain in the back of her knee that limited her movement, leaving her with edema in the region.

[74] In August, at the Cleveland Open, she reached her sixth WTA Tour final, defeating qualifier Viktorija Golubic,[75] Cristina Bucșa,[76] Clara Burel,[77] and third seed Kateřina Siniaková[78] before losing to wild card McCartney Kessler.

[79] Haddad Maia won her first WTA 500 singles title at the Korea Open, defeating three Russian players, sisters Polina and Veronika Kudermetova[80] in the same day and then Daria Kasatkina in the final, in three sets.

[81][82] Beatriz Haddad Maia began her 2025 season representing Brazil in the United Cup, held in Perth, Australia.

[83][84][85] In Brazil's second tie of the event, Haddad Maia faced Laura Siegemund of Germany and lost in straight sets, 4-6, 6-7(5).

Brazil was eliminated after suffering additional defeats in singles and mixed doubles, concluding the United Cup without advancing through the group stage.

She was seeded 15th in the singles draw and faced Madison Keys in the first round but suffered a 2-6, 1-6 loss, marking her worst start to a season in four years.

[87][88][89] At the same tournament, partnering with Laura Siegemund, Haddad Maia was runner-up in the doubles, losing to Guo Hanyu and Alexandra Panova in the final.

[91][92] In her first singles match, Haddad Maia faced the Argentine player Julia Riera and won in three sets, with a score of 4/6 7/5 6/2.

[110] At the end of 2023, Haddad signed a sponsorship with the American jewelry trading company Tiffany & Co., and it is expected that she will wear the brand's products during the 2024 Grand Slam tournaments and at the 2024 Summer Olympics in Paris.