Sheila Garrity, a former campaign manager for President Catherine Connolly, is to stand in the Galway West by-election.
The Dáil seat was vacated by Ms Connolly after she was elected head of state last year.
Sheila Garrity worked on the former TD's local, general and presidential election campaigns over the last two decades.
She is the second candidate to declare for the by-election this week after Independent Councillor Thomas Welby threw his hat into the ring.
The Oughterard-based local representative has links with sitting TD and Minister of State, Noel Grealish.
He will be hoping to draw on the support that his former Progressive Democrats colleague has and combine it with his own established personal vote.
Cllr Welby identified housing and traffic as areas most urgently in need of attention.
Ms Garrity said that her campaign will prioritise fairness, dignity and an awareness of the issues impacting people across the constituency.
Her decision to contest the by-election follows discussions in recent months locally on how experiences from the presidential race could inform future elections.
Ms Connolly was first elected in Galway West in 2016, on her third attempt. She enhanced her share of first preferences in subsequent elections, taking close to 7,000 of them, in 2024.
The destination of those votes will be key to determining who fills the fifth seat in the constituency.
A number of individuals and parties have yet to finalise their plans.
Sinn Féin, Fianna Fáil and Fine Gael are expected to select candidates in the coming weeks.
Several smaller parties and independents are also expected to enter the fray.
Independent Ireland will run Cllr Noel Thomas, Cllr Helen Ogbu will be the Labour candidate and Niall Murphy is standing for the Green Party.
The by-election is expected to take place in April or early May.
