Twain's manager Jason Owen confirmed that Twain is engaged to business executive Frederic Thiebaud. Owen declined further comment.
The news was first reported by Us Weekly.
Twain first confirmed in August 2009 that she was dating Thiebaud after her divorce from Robert "Mutt" Lange, who had an affair with Twain's best friend and Thiebaud's wife, Marie-Anne Thiebaud.
She reached out to Frederic Thiebaud in the aftermath, and wrote on her website last year that she had found "a dear friend and true gentleman."
No word on when or where the wedding will be. Twain, who has stepped away from the spotlight the last few years, has an autobiography due out in the spring and is scheduled to have her own show on Oprah Winfrey's television network.
