2018 Oracle Challenger Series – Newport Beach – Women's singles

This was the first edition of the tournament.

Wildcard Danielle Collins won the title, defeating Sofya Zhuk in the final 2–6, 6–4, 6–3.

Seeds
• # 🇺🇸 Christina McHale (first round)

• # 🇺🇸 Alison Riske (first round)

• # 🇺🇸 Taylor Townsend (first round)

• # 🇮🇹 Francesca Schiavone (first round)

• # 🇺🇸 Sofia Kenin (first round)

• # 🇺🇸 Sachia Vickery (quarterfinals)

• # Ajla Tomljanović (semifinals)

• # 🇨🇴 Mariana Duque Mariño (first round)

Seeds
• # 🇺🇸 Caroline Dolehide (qualifying competition)

• # 🇨🇿 Marie Bouzková (qualified)

• # 🇷🇺 Sofya Zhuk (qualified)

• # 🇺🇸 Amanda Anisimova (qualified)

• # Daniela Seguel (qualified)

• # 🇺🇸 Louisa Chirico (first round)

• # 🇭🇺 Fanny Stollár (first round)

• # 🇺🇸 Danielle Lao (qualifying competition)

• # 🇧🇬 Elitsa Kostova (qualified)

• # 🇫🇷 Amandine Hesse (qualifying competition)

• # 🇯🇵 Mayo Hibi (qualified)

• # 🇺🇸 Usue Maitane Arconada (first round)

Qualifiers
• # 🇧🇬 Elitsa Kostova

• # 🇨🇿 Marie Bouzková

• # 🇷🇺 Sofya Zhuk

• # 🇺🇸 Amanda Anisimova

• # Daniela Seguel

• # 🇯🇵 Mayo Hibi