People magazine reported Dean Sheremet and photographer Sarah Silver announced plans to wed, but it did not give a date for the ceremony.
"Congrats to @deansheremet and @sarah_silver on your engagement!," Grammy winner Rimes tweeted Saturday. "A little birdie told me the happy news last night. Wishes for a life full of happiness."
Rimes and Sheremet split a little more than a year ago after seven years of marriage. Rimes had admitted to an extra-marital affair with her current beau Eddie Cibrian.
"My congrats is from my heart. Sorry if you don't understand it. I do not need the publicity, I get plenty. Please stop passing (judgment)" Rimes tweeted.
Speculation abouts about a pending engagement announcement by Rimes, 28, and Cibrian, People said.
"Eddie and I are beyond happy and in love and look forward to one day sharing such private news with you all," Rimes wrote. "Hopefully will be able to enjoy it privately and share it with our family and friend's before the world knows."