The Bridget Jones's Diary star, 43, was pictured kissing a tall, dark-haired man at the Los Angeles International Airport on Wednesday.
Her mystery man was quickly identified as guitarist and producer Doyle Bramhall II, also 43, who previously dated Sheryl Crowe in 2011 after meeting on tour as her guitarist.
An insider told Us Weekly that Zellwegger and Bramhall went to college together in Texas, adding of their budding romance:
"It's going really well."
The pair were packing on the PDA at the airport, sharing a kiss in their coordinating jeans, dark coats and sunglasses.
The actress was previously married to country star Kenny Chesney in 2005, but the pair split after only four months.
She was later reportedly dating her Case 39 costar Bradley Cooper for more than a year.
She and the actor split in March 2011, and Cooper is currently dating actress Zoe Saldana.
Zellwegger's other Hollywood romances include Jim Carrey and Jack White.