Smiling, holding hands and sporting baseball caps and sunglasses, the couple were spotted on Saturday at a farmer's market in Ojai, which is in Ventura County, near Santa Barbara.
Witherspoon, whose actual birthday is Monday, has been linked to Toth, 39, since early February. She and Jake Gyllenhaal quietly split in December.
The quiet weekend was in contrast to the Oscar winner's 33rd birthday, when she was feted with a surprise birthday party at the Los Angeles premiere of Monsters vs. Aliens.
– Tim Nudd