The Green Party has voted to go into government with Fine Gael and Fianna Fáil.
It clears the way for the Fianna Fáil / Fine Gael / Greens government to be formed, after the other two parties also backed the deal earlier on Friday.
Fianna Fáil leader Micheál Martin is now expected to be elected as Taoiseach by the Dáil tomorrow.
The Greens had needed a two-thirds majority of members to approve the deal in a postal ballot.
Almost 1,900 members of the party cast their votes - with the final result 76% to 24% for no.
It was earlier confirmed that members of Fine Gael had backed the deal overwhelmingly, with 80% voting yes and 20% voting no.
There was also strong support for the deal with Fianna Fáil, with 74% of their members voting in favour of the deal.
With the programme for government now approved by the individual parties, the Dáil will hold a special sitting at the Convention Centre Dublin tomorrow to elect a new Taoiseach.
Under the coalition deal, Deputy Martin will hold the role until December 2022, with Leo Varadkar to take over then for the remainder of the new government's term.
If approved, Micheál Martin will tomorrow also appoint his Cabinet ministers.