The two-time Academy Award winner, 52, and the Wheeler Dealers star, 42, are dating, PEOPLE can confirm.
On Monday, PEOPLE confirmed Anstead and HGTV star Christina Haack, 37, had finalized their divorce.
Zellweger, meanwhile, was previously married to Kenny Chesney for a brief period in 2005, and was in a relationship with Jim Carrey from 1999 to 2000.