Mary Pierce defeated Ai Sugiyama in the final, 6–0, 6–3 to win the singles tennis title at the 2005 Southern California Open.
Lindsay Davenport was the reigning champion, but withdrew due to a lower-back strain.
Seeds The top eight seeds received a bye into the second round.
Draw
Finals
Top half
Section 1
Section 2
Bottom half
Section 3
Section 4
External links ITF tournament draws