2021 Rancho Santa Fe Open

The 2021 Rancho Santa Fe Open was a professional women's tennis tournament played on outdoor hard courts. It was the eleventh edition of the tournament which was part of the 2021 ITF Women's World Tennis Tour. It took place in Rancho Santa Fe, California, United States between 11 and 17 October 2021.

Seeds

 * 1 Rankings are as of 4 October 2021.

Other entrants
The following players received wildcards into the singles main draw:
 * 🇺🇸 Hanna Chang
 * 🇺🇸 Kayla Day
 * 🇺🇸 Jessica Failla
 * 🇺🇸 Allie Kiick

The following player received entry using a protected ranking:
 * 🇦🇺 Priscilla Hon

The following player received entry as a junior exempt:
 * 🇫🇷 Elsa Jacquemot

The following player received entry as a special exempt:
 * 🇺🇸 Emina Bektas

The following players received entry from the qualifying draw:
 * 🇺🇸 Ellie Douglas
 * 🇺🇸 Haley Giavara
 * 🇺🇸 Dalayna Hewitt
 * 🇺🇸 Elvina Kalieva
 * 🇺🇸 Ashlyn Krueger
 * 🇺🇸 Maegan Manasse
 * 🇸🇰 Tereza Mihalíková
 * 🇫🇷 Marine Partaud

Singles

 * 🇸🇪 Rebecca Peterson def. 🇺🇸 Elvina Kalieva, 6–4, 6–0.

Doubles

 * 🇵🇱 Katarzyna Kawa / 🇸🇰 Tereza Mihalíková def. Liang En-shuo / 🇨🇦 Rebecca Marino, 6–3, 4–6, [10–6].