Mr. Delargy, aged 25, is a keen Gaeilgeoir with an interest in Gaelic football and Irish traditional music.
In 2018, Pádraig played a key role in establishing the Patricia Hughes Bursary Scheme in memory of his late aunt.
Ms. Ferguson grew up in Strabane and is qualified with a First-Class BSc in Housing.
She also completed a PGDip in Management from the North West Regional College and a PG Advanced Dip in Sustainable Investment for the Third Sector from the Ulster University Business School at Jordanstown.
She has been the Chairperson of the Outer North Neighbourhood Renewal Partnership for over 11 years.
Speaking after the party held a selection convention in the city on Wednesday night, Donegal TD Pearse Doherty commented: "I would like to congratulate Pádraig Delargy and Ciara Ferguson tonight on their selection as the newest MLAs to represent Sinn Féin and Derry in the Assembly, subject to approval by the Ard Chomhairle.
"Pádraig and Ciara will both bring a great deal of experience and enthusiasm to our Assembly team at such a crucial time for politics across the island of Ireland and a new era for Sinn Féin in Derry.
“They will a play huge role in helping to establish Derry and the north west as a thriving, modern city with more jobs, more social and affordable homes and ensure that commitments to Magee, the detox centre and health services are honoured."
Deputy Doherty paid tribute to the new MLAs predecessors.
“I also want to thank outgoing MLAs Karen Mullan and Martina Anderson for all the hard work they have done on behalf of this constituency and Sinn Féin as they take up new important roles in the party.”