Ryan announced the pair’s engagement on Thursday via Instagram.
“Engaged,” Ryan wrote simply.
Her announcement included a quirky, hand-drawn photo of her and Mellencamp.
The two have dated off and on since 2011, according to People.
This will be Ryan’s second marriage. She was previously married to actor Dennis Quaid for ten years.
Mellencamp has previously been married three times.
No word on whether they’ll serve coconut cake with chocolate sauce on the side at the wedding.