Kildare North Social Democrats TD Aidan Farrelly has welcomed the move, saying Ms Connolly has been a strong voice for peace, human rights, and progressive causes.
The Social Democrats have become the first party to nominate a candidate for the upcoming presidential election.
The party’s National Executive has formally backed independent TD Catherine Connolly, who represents Galway West.
The nomination secures her 12 Oireachtas signatures - eight short of the 20 required to appear on the ballot.
Kildare North Social Democrats TD Aidan Farrelly has welcomed the move, saying Ms Connolly has been a strong voice for peace, human rights, and progressive causes.
Deputy Connolly is expected to formally launch her presidential campaign next week.

New Appeals System For Asylum Seekers Comes Into Effect
Bord Bia Review Published In Light Of Controversy Surrounding Brazilian Beef Importation
KCC Report Reveals North Vs South Divide In Kildare
Kildare TD Highlights Difficulties Faced By Wheelchair Users In Curragh School
"A Fall Every Week" : Mayor Of Naas Calls For Alterations To Kilcullen Road
Local TD Accepts Data Centres Are A "Particular Issue" In Ireland
Kildare Dog Shortlisted For Bravest Pet Award
Kildare Senior Football Team vs Kerry