The 2018 Oracle Challenger Series – Newport Beach was a professional tennis tournament played on outdoor hard courts. It was the first edition of the tournament, which was part of the 2018 ATP Challenger Tour and the 2018 WTA 125K series. It took place January 22 through 28, 2018 in Newport Beach, United States.
The following players received wildcards into the singles main draw:
The following players received entry from the qualifying draw:
The following players received wildcards into the singles main draw:
The following players received entry from the qualifying draw:
Jennifer Brady → replaced by 
Jang Su-jeong Madison Brengle → replaced by .svg/1280px-Flag_of_Switzerland_(Pantone).svg.png){kind=small}
Stefanie Vögele
Danka Kovinić → replaced by .svg/1280px-Flag_of_Canada_(Pantone).svg.png){kind=small}
Carol Zhao Varvara Lepchenko → replaced by Jil Teichmann Taylor Fritz def. Bradley Klahn 3–6, 7–5, 6–0. James Cerretani / 
Leander Paes def. 
Treat Huey / Denis Kudla 6–4, 7–5. Danielle Collins def. 
Sofya Zhuk 2–6, 6–4, 6–3
Misaki Doi / Jil Teichmann def. Jamie Loeb / 
Rebecca Peterson 7–6(7–4), 1–6, [10–8]
