The British singer popped the question to dental nurse Rosanna Jasmin during a romantic getaway in Paris, France on Monday (23Dec13).
A statement on Blue's official Facebook.com page reads, "It is with great pleasure we are pleased to announce the engagement of Antony Costa and his beautiful girlfriend Rosanna. Antony surprised Rosanna on her birthday today with a visit to Paris where he asked for her hand in marriage and she happily said yes.
"Everyone in Blue and the entire management team wish both Rosanna and Antony the very best for the future and we are all looking forward to the wedding."
The singer has since taken to Twitter.com to thank his fans for their messages, writing, "Thank you for your lovely messages myself and Rosanna Jasmin are so happy to announce our engagement!!! Bring on 2014 xxx."
Costa and Jasmin went public with their relationship in June last year (12).