Career
He was a Teachta Dála (Territorial Decoration) for constituencies in County Galway for over thirty years, and then a Senator for 8 years. He was elected to Dáil Éireann on his first attempt, at the June 1927 general election in the nine-seat Galway constituency. He took his seat in the 5th Dáil, along with the 44 other Fianna Fáil TDs who ended the Republican policy of abstentionism and took the disputed oath of allegiance, dismissing it as an "empty formula".
He was re-elected at the September 1927 general election.
He was re-elected the following year, displacing Cumann na nGaedheal"s Joseph Mongan. Killilea was then re-elected at all the eight general elections in the next 28 years, switching to the new Galway East constituency when the county"s parliamentary representation was split at the 1937 election, and choosing Galway North after a further constituency revision for the 1948 general election.
At the 1961 general election, he lost his seat again, this time in the restored Galway East constituency. The county"s three 3-seat constituencies had been replaced by the 3-seat Galway West and the 5-seat Galway East, where Killilea was one of four sitting Fianna Fáil TDs who stood for re-election.
He then stood for election to Seanad Éireann on the Labour Panel, and was returned to the 10th Seanad.