"Scotty and I had a great year together as we travelled the world and crossed a lot of things off our bucket list," the actor said, referring to Rossi's legal name, Scottine. "She's a terrific gal — but we've mutually decided to go our separate ways and not spend the rest of our lives together."
"I've decided that my children deserve my focus more than a relationship does right now. I still have a tremendous fondness for Scotty and I wish her all the best," Sheen added.
The pair had planned on marrying in November, a year after they met. They had been engaged since February, when the former Two and a Half Men star proposed on a Valentine's Day trip to Hawaii.
This would have been the fourth marriage for Sheen, who was previously married to Donna Peel (1995-1996), Denise Richards (2002-2006) and Brooke Mueller (2008-2011). Sheen was also engaged to Kelly Preston in 1990, but the relationship ended shortly after he accidentally shot her in the arm.
Scandal Supercut! Relive every awesome drunk Mellie moment: