Mr Adams announced in November that he was stepping down as Sinn Fein president after 34 years in the role.
Deputy McDonald's succession to president-elect comes after Gerry Adams previous year announced he would be standing down as his party's leader in 2018.
Sinn Fein has shared power in Northern Ireland since 2007 and is in negotiations to try to restore the devolved executive there but it has never governed in the south.
Sinn Fein's governing council met in Belfast to formally ratify Ms McDonald, with a special conference to elect her to be held next month when Mr Adams, 69, steps down after nearly 35 years at the helm.
"I won't fill Gerry Adam's shoes but I've brought my own and together we will walk a journey that will lead to a United Ireland".
Addressing the Belfast meeting, Ms McDonald said she believes her leadership will mark a defining chapter in the achievement of a United Ireland.
Ms McDonald has been a TD for Dublin Central since 2011.
"This is also my last Ard Fheis as Uachtaran Sinn Fein - I will be asking the incoming Ard Comhairle to agree a date in 2018 for a special Ard Fheis to elect a new Uachtaran".
Several party members took to Twitter to express their support for Ms McDonald.
I am proud and honoured to be nominated for Uachtarán Shinn Féin.
I believe we are capable of achieving anything that we set our minds to.
Meanwhile, Mr Adams has said that Sinn Fein wants to see an end to the year-long political stalemate at Stormont. Mr Adams said his deputy would enter the fray at a "very polarised and very toxic" time in Irish politics but said that there was "no merit" in disengaging from talks with unionists.
They were allegedly punished when they washed their hands above their wrists, and beaten regularly, according to the prosecutor. "She used to say how the would be ideal for TV and would often mention they would be bigger than reality show Kate Plus 8".
A week after his shocking death, the Phillies and the Toronto Blue Jays at Spectrum Field, the Phillies' spring training home. The coroner lists the cause of Halladay's death as blunt trauma and drowning, but also says he had morphine in his system.
With their broadcasts offline, it'll be a lot trickier for any overseas troops or their families to watch the games. Several military members even took to the AFN Europe's Facebook page to complain about the situation.
The final list for SCM was announced on Friday. "These 9 cities have approximately 409 projects", Puri added. Shillong will be the 100th city provided it submits its proposal to the Centre in next three months.
But already the two Koreas have said they will march together at the opening ceremony under the Korean unification flag. As long as the present family dictatorship runs North Korea there will be no peace treaty .
I bet she screams in the sack.' I protested, 'Please, don't talk like that. 'Hey, thank you, you're good. Douglas used crude language in one-on-one meetings with Braudy, she said, and would comment on her body.
Last week two beta updates were rolled out, and this fast pace may indicate that iOS 11.2.5 is nearly ready for prime time. He didn't exactly say why, but it's likely he doesn't want iPhone users to experience unexpected restarts.
Investigators look for clues at the rear of accused serial killer Bruce McArthur's 20-acre property north of Madoc. Toronto police said they believe the two men may not be McArthur's only victims, but refused to elaborate further.
Russian President Vladimir Putin marches towards the icy-cold waters of Lake Seliger in Svetlitsa village, Russia, 19-01-2018. In the video, he can be seen blessing himself as he lowers himself into the water wearing only his swimming trunks.
IN official says state will be careful in Amazon offer
They said inquiries made to Amazon immediately after its original announcement were met with interest. "It shouldn't be that way. We are working hard to address these challenges, but we suspect they factored heavily in Amazon's decision to look elsewhere".
WhatsApp Business finally launches on Android
The business accounts will be clearly identifiable, so the consumers know that they are interacting with a business account. They will have all the existing features like blocking any number including the businesses, and report the spam.
Repeated Hits to the Head - Not Concussions - May Cause CTE
Let's start with the obvious: Four teenaged brains and some mice can't support sweeping conclusions about the causes of CTE. They found early evidence inside the brain consistent with signs of CTE, including abnormal accumulation of tau protein.