Sheriff's spokesman Sgt. Tim Curran says deputies arrested Barnes after responding to what was termed an incomplete 911 call from a home around 4:16 p.m. Wednesday.
Deputies say both Barnes and the woman had visible injuries, but took Barnes into custody after determining he had been the primary aggressor.
The name of the woman was not released, but she was described by authorities as "a woman who lived with him and with whom he had a dating relationship."
Barnes was booked into the Sacramento County Jail on suspicion of domestic violence and maliciously obstructing the use of a telephone line.
He posted a $50,000 bond and was released. He is scheduled to be arraigned in court Monday.
Aaron Goodwin, Barnes' agent, reached in Turkey by ESPNLosAngeles.com, said in a text message that he was "getting the facts first from both parties" before commenting further.
"I plan to find out accurately what transpired, and go from there," Goodwin said via text.
Barnes, who attended UCLA, signed a two-year, $3.6 million contract with the Lakers in July.
Information from ESPNLosAngeles.com's Dave McMenamin and The Associated Press was used in this report.