| Doubles | |
|---|---|
| 2018 Korea Open | |
| Champions |  Choi Ji-hee Han Na-lae |
| Runners-up |  Hsieh Shu-ying Hsieh Su-wei |
| Score | 6–3, 6–2 |
| Draw | 16 |
| Seeds | 4 |
Kiki Bertens and Johanna Larsson were the defending champions, but Bertens chose not to participate. Larsson played alongside Mona Barthel, but lost in the semifinals to Hsieh Shu-ying and Hsieh Su-wei.
Choi Ji-hee and Han Na-lae won the title, defeating Hsieh and Hsieh in the final, 6–3, 6–2.
Irina-Camelia Begu / Raluca Olaru (quarterfinals)
Dalila Jakupović / 
Darija Jurak (quarterfinals)
Ellen Perez / Arina Rodionova (semifinals)
Mona Barthel / 
Johanna Larsson (semifinals)| First round | Quarterfinals | Semifinals | Final | ||||||||||||||||||||||||
| 1 | I-C Begu R Olaru | 6 | 77 | ||||||||||||||||||||||||
 J Cako N Geuer | 4 | 65 | 1 | I-C Begu R Olaru | 6 | 1 | [8] | ||||||||||||||||||||
| S-y Hsieh S-w Hsieh | 6 | 6 | S-y Hsieh S-w Hsieh | 3 | 6 | [10] | |||||||||||||||||||||
 AK Schmiedlová T Zidanšek | 4 | 4 | S-y Hsieh S-w Hsieh | 3 | 6 | [12] | |||||||||||||||||||||
| 4 | M Barthel J Larsson | 6 | 77 | 4 | M Barthel J Larsson | 6 | 1 | [10] | |||||||||||||||||||
C Škamlová  E Wacanno | 4 | 65 | 4 | M Barthel J Larsson | 77 | 3 | [10] | ||||||||||||||||||||
| WC | S-j Jang N-r Kim | 2 | 64 |  L Kumkhum P Plipuech | 64 | 6 | [8] | ||||||||||||||||||||
| L Kumkhum P Plipuech | 6 | 77 | S-y Hsieh S-w Hsieh | 3 | 2 | ||||||||||||||||||||||
 H Dart B Schoofs | 5 | 1 | WC | J-h Choi N-l Han | 6 | 6 | |||||||||||||||||||||
 B Štefková R Voráčová | 7 | 6 | B Štefková R Voráčová | 0 | 4 | ||||||||||||||||||||||
 C Liang Q Ye | 4 | 1 | 3 | E Perez Ar Rodionova | 6 | 6 | |||||||||||||||||||||
| 3 | E Perez Ar Rodionova | 6 | 6 | 3 | E Perez Ar Rodionova | 1 | 1 | ||||||||||||||||||||
P Hon  Y Sizikova | 3 | 77 | [4] | WC | J-h Choi N-l Han | 6 | 6 | ||||||||||||||||||||
| WC | J-h Choi N-l Han | 6 | 62 | [10] | WC | J-h Choi N-l Han | 7 | 4 | [10] | ||||||||||||||||||
A Rus  N Stojanović | 0r | 2 | D Jakupović D Jurak | 5 | 6 | [5] | |||||||||||||||||||||
| 2 | D Jakupović D Jurak | 2 | |||||||||||||||||||||||||
Mathilde Johansson was the defending champion, and successfully defended her title, defeating Petra Cetkovská in the final, 7–5, 6–3.
Caroline Wozniacki was the defending champion, but lost to Angelique Kerber 6–4, 6–4 in the final.
Garbiñe Muguruza was the defending champion heading into the tournament but chose to compete at the Sydney tennis event instead of Hobart. In the final, it was unseeded Brit Heather Watson who defeated the American qualifier in Madison Brengle, 6–3, 6–4 to record her second WTA title.
Lara Arruabarrena and Irina-Camelia Begu were the defending champions but chose not to participate together. Begu teamed up with Raluca Olaru but lost in the semifinals to Kiki Bertens and Johanna Larsson.
Arruabarrena successfully defended the title alongside Andreja Klepač, defeating Kiki Bertens and Johanna Larsson in the final, 2–6, 6–3, [10–6].
Timea Bacsinszky and Kristina Barrois were the defeating champions, but chose not to participate this year.
Heather Watson was the defending champion, but lost in the quarterfinals to Johanna Larsson.
Kiki Bertens and Johanna Larsson were the defending champions, but withdrew from their semifinal match.
Han Xinyun and Christina McHale won the title, defeating Kimberly Birrell and Jarmila Wolfe in the final, 6–3, 6–0.
This is the first edition of the tournament since 1994.
Mona Barthel and Laura Siegemund were the defending champions, but Barthel chose not to participate this year. Siegemund played alongside Antonia Lottner, but lost in the first round to Annika Beck and Xenia Knoll.
Elise Mertens and An-Sophie Mestach were the defending champions, but Mestach chose not to participate this year and Mertens chose to compete in Brisbane instead.
Elina Svitolina defeated Simona Halep in the final, 4–6, 7–5, 6–1 to win the women's singles tennis title at the 2017 Italian Open.
Dominika Cibulková was the defending champion, but lost in the second round to Heather Watson.
Viktorija Golubic was the defending champion, but lost in the first round to Antonia Lottner.
Chan Yung-jan and Martina Hingis defeated Lucie Hradecká and Kateřina Siniaková in the final, 6–3, 6–2 to win the women's doubles tennis title at the 2017 US Open. It was their first Grand Slam title together, and their seventh title overall, all in 2017.
Kirsten Flipkens and Johanna Larsson were the defending champions, but Flipkens chose not to participate this year.
Tímea Babos and Andrea Hlaváčková defeated Kiki Bertens and Johanna Larsson in the final, 4–6, 6–4, [10–5] to win the doubles tennis title at the 2017 WTA Finals.
Tímea Babos and Kristina Mladenovic won the women's doubles tennis title at the 2018 Australian Open, defeating Ekaterina Makarova and Elena Vesnina in the final, 6–4, 6–3. It was the first Grand Slam title for Babos, who became the first Hungarian player to win a Grand Slam event since Andrea Temesvári in the 1986 French Open and the second Grand Slam title for Mladenovic.
Latisha Chan and Martina Hingis were the defending champions, but Hingis retired from professional tennis at the end of 2017. Chan played alongside her sister Chan Hao-ching, but lost in the second round to Hsieh Su-wei and Barbora Strýcová.
Petra Kvitová defeated Kiki Bertens in the final, 7–6(8–6), 4–6, 6–3 to win the women's singles tennis title at the 2018 Madrid Open. It was Kvitová's third Madrid Open title, and she became the first player to win three women's singles titles at the Madrid Open.
Jeļena Ostapenko was the defending champion, but lost in the second round to Ekaterina Alexandrova.