Teuila Blakely says she has been kicked in the head and dragged down the hallway by her hair by abusive ex-partners.
The Dancing With the Stars competitor says she was battered so badly in one attack her jaw remains out of alignment.
She said her injury serves as "a constant reminder of one of the lowest points of my life".
Blakely, whose chosen charity on DWTS is Woman's Refuge, reveals her struggles with domestic abuse for the first time in this week's edition of Woman's Day.
The 40-year-old says she grew up surrounded by violence, so being treated badly by partners seemed "normal".
"When I first got hit by a partner, I didn't see that as unusual. And these guys all came from the same kind of background as me," she said.
"Then when the hitting became beatings and the beatings became more common ...
"Well, again, it's not that uncommon."
Blakely says she was involved in another relationship with a man who "constantly belittled me".
"He said I was fat and made me feel self-conscious about my appearance and myself in general.
"I became so unconfident, I couldn't even get out of the car at the shops. I spent years with my head down in case I looked at anyone and it upset him ... which I would get in trouble for."
Blakely told WD she was speaking out to help others who might be in a similar situation, and to urge those who knew of people in abusive relationships to speak out.
"Hopefully women stuck in touch domestic situations - whether they be physically violent or emotionally abusive, or both - will hear my story and know the future can still be bright.
"I don't like to dwell on the bad things in my past, but if some good can come from it, I'd like that."
Blakely has appeared on Shortland Street, the Outrageous Fortune prequel Westside, and is currently competing in TV3 reality show Dancing With the Stars.
Where to get help:
• Police Emergency: 111
• Women's Refuge: 0800 733 843
• Victim Support: 0800 842 846
• Lifeline: (09) 522 2999
• Family Violence Info Line: 0800 456 450