[4] Ashleigh Barty began the year at the Hopman Cup where she teamed up with Matthew Ebden but ended up second in their group thus failing to reach the final.

She then represented Australia in Fed Cup where they faced United States in the quarterfinals where they won with Barty winning both her matches.

At the Sunshine Double, she reached the fourth round of the BNP Paribas Open but lost to Elina Svitolina in three sets.

She, however, bounced back by winning her first Premier Mandatory event at the Miami Open defeating Karolína Plíšková in the final in two tight sets.

The grass-court season she began with her third title of the year at the Birmingham Classic defeating Julia Görges and in the process also claiming the world No.

[5] Karolína Plíšková began the year by winning the Brisbane International defeating Lesia Tsurenko in the final in three sets.

She began her grass season at the Birmingham Classic but lost to sister Kristýna in the second round in a third set tiebreak.

She had another poor slam run at the US Open, when she lost to Johanna Konta in the fourth round despite leading their head-to-head 6-1 prior to the match.

Her clay-court season started at the Madrid Open, where she reached the final before losing to Kiki Bertens in straight sets.

Tipped as the huge favourite at Roland Garros, Halep fell to a shock defeat against talented youngster Amanda Anisimova in the quarterfinals and hence ending her title defence.

Similar to previous years, she struggled during the Asian swing, and was plagued by a back injury which was causing her discomfort.

Bianca Andreescu began her year at the Auckland Open where she reached her first WTA final as a qualifier but lost to Julia Görges in three set.

Andreescu had a breakout tournament at the BNP Paribas Open Premier Mandatory event, when she won in three tight sets over Angelique Kerber for her first WTA tour title.

Andreescu returned to play in her home tournament, the Rogers Cup in Toronto, where she claimed the title after Serena Williams experienced back spasms and was forced to retire down 1–3 in the first set.

However, she was able to showcase her best at the Australian Open, where she lifted her second consecutive Grand Slam title after beating Petra Kvitová in a thrilling three-set contest, thus ascending for the first time in her career to the world No.

She returned to the competition at the BNP Paribas Open, where she entered the tournament as the first seed and defending champion, but ended up losing to Belinda Bencic in the fourth round.

Osaka began the clay-court season at Stuttgart, where she reached the semifinals before withdrawing from her match against Anett Kontaveit due to an abdominal injury.

Osaka went on to finish the clay-court swing with a shocking third-round loss to Kateřina Siniaková at the French Open, which ended her 16-win streak at Grand Slam tournaments.

Osaka entered the Birmingham Classic as the first seed but she lost in the second round to Yulia Putintseva in straight sets.

Osaka resumed competition at the Rogers Cup and Western & Southern Open, reaching the quarterfinals, where she lost to Serena Williams and Kenin (by retirement), respectively.

At the Italian Open, her first appearance there since 2016, Kvitová made the third round where she faced Sakkari but retired with an injured calf while trailing in the decider.

Returning to competition at Wimbledon after a six-week layoff, sixth-seeded Kvitová cruised to the fourth round, her first appearance in the second week there since winning the title in 2014, but lost to 19th seed Johanna Konta in three sets.

[9] Elina Svitolina opened the season with an unsuccessful title defense at the Brisbane International, where she lost her first match to the previous year's finalist, Aliaksandra Sasnovich.

She rebounded by reaching the quarterfinals of the Australian Open, where she was defeated by eventual champion Naomi Osaka in straight sets.

After losing in her opening rounds at the Birmingham Classic (to Margarita Gasparyan) and Eastbourne International (to Alizé Cornet), Svitolina proceeded to reach her first Grand Slam semifinal at Wimbledon, she faced eventual champion Simona Halep and was defeated in straight sets.

Svitolina's North American hard-court season began at the Silicon Valley Classic, where as the top seed, she fell to Maria Sakkari in the quarterfinals.

[10] Belinda Bencic began her year at the Hopman Cup, where she represented Switzerland with Roger Federer, they won the title defeating Germany in the final.

She reached the semifinals at the Hobart International to Anna Karolína Schmiedlová and made it to the third round at the Australian Open, losing to eventual finalist Petra Kvitová.

Bencic continued her win streak with a semifinal appearance at the BNP Paribas Open losing to Angelique Kerber.

During the grass court season, Bencic made her second WTA final of the year at the Mallorca Open, but finished runner-up to Sofia Kenin despite having three match points in the second set.