"If anyone's heard the rumors of my engagement, they are absolutely true! Vanessa and I couldn't be happier," Lachey Tweeted on Thursday.
People magazine reports 36-year-old Lachey popped the question near a beach in California.
The couple began dating in 2006 before splitting briefly in 2009.They have not announced a wedding date.
The former 98 Degrees singer was previously married to Jessica Simpson, and the two starred the MTV reality show "Newlyweds: Nick and Jessica" about their lives together.
