The championship was held in a bubble[a] and behind closed doors, although residents of the Mission Hills gated community were able to watch from within the boundaries of their own homes.

[3][4] Due to expected conditions in the California desert in September, with forecast temperatures in excess of 105 °F (41 °C), the LPGA allowed caddies to ride in carts for the duration of the tournament.

[5] Mirim Lee won her first major championship with a birdie at the first extra hole of a playoff with Brooke Henderson and Nelly Korda.

[9] Seven past champions were in the field; Pernilla Lindberg, Lydia Ko, Brittany Lincicome, Lexi Thompson, Stacy Lewis, Morgan Pressel and seven-time major winner Inbee Park.

Also missing were many other leading South Korean players, including Kim Hyo-joo and Lee Jeong-eun, numbers 10 and 11 respectively in the world rankings.

2020 Women's British Open champion Sophia Popov was also not in the field as her exemption for winning the first major of 2020 was not active until 2021.

[9][10] Two days prior to the tournament starting, England's world number 28 Charley Hull was forced to withdraw from the field after testing positive for COVID-19.

Up to six sponsor invitations for top-ranked amateur players Marina Alex, Brittany Altomare, Pajaree Anannarukarn, Céline Boutier, Ashleigh Buhai, Chella Choi, Chun In-gee, Carlota Ciganda, Cydney Clanton, Perrine Delacour, Austin Ernst, Jodi Ewart Shadoff, María Fassi, Dana Finkelstein, Kristen Gillman, Hannah Green, Jaye Marie Green, Georgia Hall, Nasa Hataoka, Caroline Hedwall, Brooke Henderson, Esther Henseleit, Dani Holmqvist, Caroline Inglis, Ji Eun-hee, Tiffany Joh, Ariya Jutanugarn, Moriya Jutanugarn, Danielle Kang, Yui Kawamoto, Cristie Kerr, Megan Khang, Christina Kim, In-Kyung Kim, Kim Sei-young, Katherine Kirk, Cheyenne Knight, Lydia Ko, Jessica Korda, Nelly Korda, Jennifer Kupcho, Brittany Lang, Nicole Broch Larsen, Bronte Law, Andrea Lee, Lee Mi-hyang, Minjee Lee, Mirim Lee, Stacy Lewis, Brittany Lincicome, Pernilla Lindberg, Lin Xiyu, Yu Liu, Gaby López, Nanna Koerstz Madsen, Leona Maguire, Caroline Masson, Ally McDonald, Stephanie Meadow, Olivia Mehaffey (a), Emilia Migliaccio (a), Azahara Muñoz, Yealimi Noh, Haru Nomura, Anna Nordqvist, Ryann O'Toole, Su-Hyun Oh, Amy Olson, Kaitlyn Papp (a), Annie Park, Park Hee-young, Inbee Park, Park Sung-hyun, Pornanong Phatlum, Gerina Piller, Morgan Pressel, Mel Reid, Gabriela Ruffels (a), Madelene Sagström, Lizette Salas, Sarah Schmelzel, Alena Sharp, Hinako Shibuno, Jenny Shin, Jennifer Song, Klára Spilková, Angela Stanford, Linnea Ström, Thidapa Suwannapura, Elizabeth Szokol, Emma Talley, Kelly Tan, Patty Tavatanakit, Charlotte Thomas, Lexi Thompson, Maria Torres, Ayako Uehara, Anne van Dam, Lindsey Weaver, Amy Yang, Jing Yan, Lei Ye (a), Angel Yin, Rose Zhang (a) Thursday, September 10, 2020 World number three Nelly Korda returned a six under par round of 66 to secure a one stroke lead at the conclusion of the first round.

[12][13] Ten players were tied at three under par including former ANA Inspiration winners Lydia Ko (2016) and Brittany Lincicome (2009, 2015).

On the par-5 closing hole, Lee hit her second shot over the green and, after taking a free drop from against the blue wall, proceeded to chip-in for an eagle, her third hole-out of the day, to tie Korda at 15 under par.

Playing behind Lee, Korda drove into the rough and had to lay-up short of the water guarding the front of the final green.