Merav Parsi-Zadok, in charge of communications for the campaign, made the announcement today, just hours before an official launch of the new party.
Parsi-Zadok says the party's name is "The Movement."
Livni served as foreign minister from 2006 until 2009. She was also chief peace negotiator with the Palestinians at the time.
She became the head of Israel's largest opposition party, Kadima, in 2009, but lost her bid this year to remain party leader.
Newsweek named Livni in 2011 as one of world's 150 most influential women. AP