The bar has been a mainstay of Broad Street and has remained open during the closure of the road for the construction of the Metro, which opening has been delayed again to the end of this year.
The new O'Neill's now has a capacity of 645 and now has booths with individual TV screens showing sport from across the world. The pub will also host weekly live music performances and has a brand new menu.
General manager Stef Reidy said: "We are very excited about opening our doors to the brand new O’Neills Broad Street, especially with the Commonwealth Games and World Cup still to come this year.
"We have an incredibly loyal guest base, as well as plenty of visiting trade, and we can’t wait to see their reaction."
He added: "Whilst we won’t be losing all the great stuff we are famous for, such as great food, live sport and music, we are really looking to attract some new guests who perhaps didn’t visit us previously. You can use our website or app to book yourself a table for any event and take advantage of our order at table function via the app so you never have to leave your table."
O'Neill's opens on Thursday, June 30.