The Firm actor said on The Tonight Show with Jay Leno last week that he recently proposed to his mystery girlfriend on an eventful trip to Big Sur in California.
Lucas has still not revealed his fiancée's name, but did tell Us Weekly that the couple will walk down the aisle when he gets an extended break from The Firm.
"We've been engaged for a while, but honestly, the show has been a bit of an epic undertaking, to say the least," he told the website. "We want to do it when we can enjoy it and take our time. We don't feel any stress or pressure right now and we want to make sure it stays that way."
Lucas also disclosed that he will likely hold the wedding "somewhere in nature" because he and his fiancée are both "pretty low-key".
The actor has dated several Hollywood stars in the past, including Anne Hathaway and Rachel McAdams.
The Firm airs Thursdays at 10/9c on NBC.
Watch Josh Lucas in the trailer for J. Edgar below: