Mr Kenny begins his 2,234th day as Taoiseach and therefore he overtakes John A Costello as the most successful non-Fianna Fáil leader. He achieves the record just six days shy of his 66th birthday.
However, the passing of this significant milestone has reignited calls for him to set out his timeline for departure.
Since becoming embroiled in the latest scandal revolving around Garda whistle-blower Sgt Maurice McCabe in late January, Mr Kenny has repeatedly defied calls for him to resign.
Officially, neither Mr Kenny’s office nor Fine Gael made any comment on the record being broken, but supporters of the two main contenders to succeed Mr Kenny — Simon Coveney and Leo Varadkar — said the day is fast approaching for him to announce his resignation.
Dublin North West TD Noel Rock said it is logical for Mr Kenny to stand down now.
“It is the ideal time to put on the switch. Potentially he may agree with me. He said he would be putting out a definitive timeline around this time,” Mr Rock said.
“When is the ideal time? He said he won’t lead us into the next election and confidence and supply will last for three years,” the first-time TD said on RTÉ’s Sean O’Rourke.
Mr Rock, a Varadkar supporter, said while people get leant on all the time in politics, there comes a time to speak out and stand your ground and that is what he is doing in relation to Mr Kenny. Mr Costello was Taoiseach for two stints.
The first was as head of the inter-party Government between 1948 and 1951 while he again served as Taoiseach between 1954 and 1957.
Despite overtaking Mr Costello, Mr Kenny remains well short of the record set by the first head of government of the Irish Free State, WT Cosgrave, who served as head of government for nine years and three months, or 3,381 days.
According to records, Mr Kenny becomes the seventh-longest-serving head of government since independence.
He comes after Eamon de Valera, by far the longest serving leader, Bertie Ahern, Charles Haughey, Seán Lemass, Jack Lynch, and Mr Cosgrave.
Mr De Valera served as head of government for more than two decades while Mr Kenny would need to stay in office for almost 15 months to overtake Mr Haughey’s record.