Kathleen Reynolds, the wife of former taoiseach Albert Reynolds, has died aged 88.
It is understood Mrs Reynolds died at the family home in Dublin in the early hours of Tuesday morning and had been ill for some time.
Taoiseach Micheál Martin said he was “saddened to hear of the death of Kathleen Reynolds after a long battle with illness”.
"Dedicated and steadfast, she helped husband and former Taoiseach Albert Reynolds at a crucial period in Ireland's peace process," Mr Martin said.
“My condolences to all her children and loved ones at this time.”
Former Sinn Féin leader Gerry Adams said Mr Reynolds did "more than any taoiseach before him on the peace process" and that Mrs Reynolds was "very much his partner in this work".
“She always made me welcome and I am very sorry to hear of her death,” he said. Mr Reynolds died in 2014, aged 81.