| Champ: |  Naomi Osaka |
| Runner: |  Daria Kasatkina |
| Score: | 6–3, 6–2 |
| Draw: | 96 |
| Seeds: | 32 |
| Main Name: | Indian Wells Open |
| Before Name: | BNP Paribas Open – Women's singles |
| After Name: | BNP Paribas Open – Women's singles |
See main article: 2018 BNP Paribas Open.
Naomi Osaka defeated Daria Kasatkina in the final, 6–3, 6–2 to win the women's singles tennis title at the 2018 Indian Wells Masters. It was her first WTA Tour title. This was the first time two players under 21 had contested the final since Kim Clijsters and Serena Williams in 2001.[1] At 20 years old, Osaka was the youngest Indian Wells champion since Ana Ivanovic in 2008, and the youngest at any Premier Mandatory event since Caroline Wozniacki at the 2010 China Open. She was also only the third unseeded player to win the tournament after Serena Williams (1999) and Clijsters (2005), and the first Japanese player to win a Premier Mandatory title.[1]
Elena Vesnina was the defending champion, but lost in the third round to Angelique Kerber.[2]
Simona Halep and Wozniacki were in contention for the WTA No. 1 singles ranking at the beginning of the tournament. Halep retained the top ranking after Wozniacki lost in the fourth round.
Former world No. 1 players Victoria Azarenka, Maria Sharapova and Serena Williams played in the same tournament for the first time since the 2016 Australian Open.[3] This was Azarenka's first tournament since the 2017 Wimbledon Championships and Williams' first since the 2017 Australian Open. It was also Sharapova's first appearance at Indian Wells since 2015.
All seeds received a bye into the second round.