The Bones actress will play the potentially recurring role of Bud's wife Jeannie, according to TV Line.
Described as "exhausted" and "grouchy", the character will reveal "a bit more about [Bud's] home life", according to actor John Carroll Lynch.
Lovejoy played the villainous 'Gravedigger' on Fox's Bones and also starred in HBO's The Wire from 2002 to 2008.
She has also played guest roles on Lie to Me, Law & Order: Criminal Intent and Criminal Minds.
Body of Proof returned to ABC on Tuesday night, with the second season premiere attracting 9.7m viewers.
Other stars confirmed to appear in the new season include All My Children's Chrishell Stause and The Fast and the Furious: Tokyo Drift actress Nathalie Kelly.
The series continues on Tuesdays at 10/9c on ABC.
> Body of Proof Dana Delany interview: 'I'm kind of a science nerd'
Watch a promo for the next episode of Body of Proof below: