TheDancing with the Stars professional welcomed a daughter whom she named Amalya Millan via a home birth on Saturday, Trebunskaya's representative told People.
Trebunskaya, 33, also announced her child's father is actor Nevin Millan, who has appeared in Nip/Tuck, True Blood and CSI: NY.
"We're thrilled to welcome our beautiful, healthy baby into the world. We couldn't be happier," the couple reportedly said in a statement.
Trebunskaya announced she was pregnant with her first child in September 2013. She opted not to disclose any details about the baby's father at the time except that he was "very supportive," according to Us Weekly.
"It wasn't planned, but when it happened, I thought, 'This is perfect -- I'm ready to be a mom.' This is something really good for me and fulfilling, and it'll give me a whole new meaning in life. I'm really looking forward to it," the Russian dancer had told Us last year.
She had also insisted she'd quickly get back into shape and return to the ABC reality dance competition once the baby was born.
Trebunskaya has appeared on 10 seasons of Dancing with the Stars. The closest she's ever come to winning was when she finished in the runner-up spot with Jerry Rice in Season 2 and Evan Lysacek in Season 10.