Leo Varadkar will be elected the youngest ever Taoiseach when the Dáil meets this afternoon.
He's expected to secure at least 58 votes in the Dáil and with Fianna Fáil abstaining that will guarantee him victory.
After traveling to Aras an Uachtaráin to collect his seal of office, Mr Varadkar will return to Government Buildings and announce a reshuffled Cabinet.
He's already appointed his defeated colleague in the leadership race – Simon Coveney - as deputy leader of FG, and Mr Coveney is expected to move into the Department of Foreign Affairs and Trade.
Many of the Fine Gael ministers are expected to move portfolios or be given additional responsibilities - like Paschal Donohoe who will become finance minister.
Mayo-based Junior Minister Michael Ring is among those tipped for promotion to the Cabinet table.
Meanwhile, Mayo’s Enda Kenny has ended his six years as Taoiseach, by handing his resignation to the President yesterday evening.
He remains in the role on a caretaker basis until Leo Varadker’s appointment later today.
The Dail will gather at noon and a vote on Mr Varadkar's appointment is expected at around 2 o'clock.