The Sk8er Boi hitmaker, 30, wed the Nickelback frontman, 40, in July, 2013 after a whirlwind romance, but they have been dogged by rumours of an impending split for the past year, and on Wednesday (02Sep15), the unlikely couple finally confirmed the news.
Lavigne took to Instagram to share a photo from the stars' wedding day, and captioned it, "It is with a heavy heart that Chad and I announce our separation today.
"Through not only the marriage, but the music as well, we've created many unforgettable moments. We are still and forever will be, the best of friends, and will always care deeply for each other. To all our family, friends and fans, thank you sincerely for the support."
The separation announcement comes just days after Lavigne's ex-husband Deryck Whibley tied the knot. The Sum 41 star exchanged vows with his fiancee Ariana Cooper on Sunday (30Aug15) in Los Angeles.
Lavigne and Whibley were married from 2006 to 2010.