The 29-year-old singer and 39-year-old Nickelback frontman have been married 14 months, and are reportedly on the brink of breaking up.
"It's over," a source told Us Weekly. "He has been going around LA telling people that they are divorcing."
The couple celebrated their one-year wedding anniversary July 1, and Kroeger gave his wife a 17-carat emerald-cut diamond to mark the occasion. Lavigne proudly shared a photo of the ring on Twitter, but has since deleted the post.
Lavigne was previously married to Sum 41 frontman Deryck Whibley from 2006 to 2010. She and Kroeger started dating in July 2012, and got engaged one month later. The singer released her fifth studio album, Avril Lavigne, in 2013.