Born in Woodlawn, County Galway, Kett was an administrator of the Central Remedial Clinic. He was reportedly a key member of the "Drumcondra Mafia", as Bertie Ahern's inner circle of constituency supporters are dubbed.[4]
He was co-opted as member of Dublin City Council for the North Inner City electoral area in 1988 to replace Bertie Ahern (who had resigned when he was appointed a government minister) and was re-elected at the 1999 local elections.[5] With the abolition of the dual mandate, he did not contest the 2004 local elections.[6]