Florence Noonan (68) contracted pneumonia two weeks ago and died surrounded by her family at the Milford Care Centre in Castletroy, Co Limerick late last night.
The mother-of-five who played an active part in Mr Noonan’s political career until her illness, is survived by her husband and children Tim, John, Michael, Orla and Deirdre.
For more than 13 years, Florence, a native of Castlemaine, Co Kerry and a hugely popular figure around Noonan's homebase in Limerick, suffered from Alzheimer's disease. She required constant care.
The onset of the illness became apparent when at the age of just 54, the former primary teacher began to forget things.
"She'd lose her keys, she'd forget to bring her handbag with her. She'd go shopping and she couldn't find the car in the car park," Noonan recalled in a moving interview with Pat Kenny on The Frontline in 2010.
Until she went into a nursing home, the TD had to combine looking after her and salvaging the remnants of his flagging political career.
He admitted that he strongly considered packing it all in as a TD.
Doctors initially thought that Florence was suffering from depression and that this was causing short-term memory loss.
"It was a concern she always had because her mother had died of Alzheimer's and it was in her head that there was a possibility, so we were all very alert when she began to forget things," he said in his Frontline interview. "She was worried, she was very worried and she was tearful. There was a lot of stress in the family.''
Florence took a full part in the 2002 General Election, Noonan recalled. "When I was out around the country doing the leader things, she was working at home and out canvassing every night."
Gradually her condition worsened, requiring the constant attention of her family. She began to suffer from seizures that were similar to epileptic fits.
Noonan recalled the fright he got on the first day that she collapsed.
"The first morning I was showering her. . . she fell out through the shower door and I couldn't catch her and she was lying on the floor.
"She was unconscious for about three quarters of an hour while we were waiting for an ambulance to come. That happened three times over a two-month period. We just couldn't carry on."
He recently told the Limerick Leader he had never received such a huge reaction as his interview about Florence's plight.
"All the burdens of caring have been transferred now from the family to personal carers,'' he said. "She's quite comfortable -- but the nature of the disease is that you have a slow decline, so she's declining slowly."
For many years Noonan lived in Buswells Hotel, just next to the Dáil, when he was in Dublin, and shot back to Limerick to look after Florence.
In recent years he moved into an apartment in Ballsbridge, and saw his wife every weekend.
Funeral arrangements for Florence Noonan have not been finalised.
Taoiseach Enda Kenny expressed his condolences to Mr Noonan saying: “On behalf of the Government, I express my deep condolences to Minister for Finance Michael Noonan on the passing of his wife, Florence," Mr Kenny said.
"Our thoughts and prayers are with Michael, their daughters and sons, and their extended family at this time of great loss."
Mr Noonan, who was married to Florence for 43 years, cancelled an engagement in Brussels for talks on the Greek bailout this week to be with his wife.
Fine Gael chairman Charlie Flanagan said the thoughts of all party members were with Mr Noonan.
"On behalf of the Fine Gael party, I would like to express our sincere condolences to our friend and colleague Michael Noonan on the sad passing of his wife, Florence," Mr Flanagan said.
"Our thoughts, our prayers and our support are with Michael and his children on the loss of a wonderful wife and mother and a fine person."
Fianna Fail leader Micheal Martin said he was deeply saddened to hear of Mrs Noonan's death last night.
"My thoughts and deepest sympathies are with Michael and his children at this difficult time," he said.
"Michael has spoken publicly in the past about the brave battle his wife has had with her condition over many years and I know this was warmly appreciated by many families across the country that are in similar circumstances.
"I want to extend my condolences, those of my party and the whole Fianna Fail organisation to Michael and his children."
Tanaiste and Labour leader Eamon Gilmore also expressed his deepest sympathies to Mr Noonan.
Mr Gilmore, who is attending an international conference on the crisis in Syria, said his thoughts were with his Cabinet colleague and his family at this very difficult time.