The Polish-born Sliwinska and the Russian-born Mazo competed on the professional Latin ballroom circuit for years before joining Dancing with the Stars' first season in 2005, when Mazo captured the trophy with General Hospital star Kelly Monaco.
People magazine reports the couple, who had a joint bachelor and bachelorette party in Las Vegas, had wanted to marry in 2006, but their dance cards were full... literally.
"We planned on getting married last year, but with the show and then the tour back to back, we had to postpone it," Sliwinska said.
This season Mazo is paired with model Josie Maran.
Meanwhile Sliwinska, the only pro dancer to appear in all five seasons of the show, is teamed with All My Children star Cameron Mathison.