"I'm not going to waste my life hating the one who won... There is no scenario or situation in which we will enter the new government. We will fight in opposition for the worldview and values - ours and that of the vast part of society that voted for us. We'll fight until we're back in power," Lapid said on Sunday.
He added that his party will support the new government if it does "something good for Israeli citizens."
Earlier on Sunday, Lapid called opposition leader Benjamin Netanyahu and congratulated him on his victory in the elections, instructing him to prepare for the transfer of power.
"I wish Netanyahu success in the name of the people of Israel and the State of Israel," Lapid's office quoted him as saying on Sunday.
On Tuesday, Israel held its fifth early parliamentary election in three years. The Likud party headed by ex-Prime Minister Benjamin Netanyahu won most of the votes and Netanyahu’s right-wing bloc secured 64 seats in the 120-seat Knesset - a confident majority. The centrist bloc of his opponents, headed by the current prime minister, the leader of the Yesh Atid party, Yair Lapid, won 51 seats.