Mark Killilea Jnr (5 September 1939 – 31 December 2018) was a farmer, auctioneer and agricultural contractor^[1] who served as an Irish Fianna Fáil politician. In a 30-year political career, served as a Teachta Dála (TD) and Member of the European Parliament (MEP) and also as a Senator.^[2]

Mark Killilea was born in Tuam, County Galway in 1939. He married Anne Severs in 1966. His father Mark Killilea Snr was a Fianna Fáil TD and a founder-member of the party. Killilea Jnr was educated locally and first held political office in August 1969, when he was elected to Seanad Éireann on the Labour Panel and re-elected in 1973. He failed to be elected to Dáil Éireann on his first attempt when he stood in Galway North-East at the 1973 general election, but at the 1977 general election he won a seat in the new Galway East constituency.^[3] The election was a landslide for Fianna Fáil and in particular showed the popularity of the party leader Jack Lynch.

However, after just two years Lynch's fortunes had changed. Along with Jackie Fahey, Tom McEllistrim, Seán Doherty and Albert Reynolds, Killilea was one of the so-called "gang of five" that lobbied the parliamentary party for support for Charles Haughey in the event of the retirement of Lynch's retirement. This group was determined that the leadership should not pass to George Colley, Lynch's apparent successor. Haughey went on to win the leadership contest and become Taoiseach in December 1979.

Killilea's loyalty to Haughey was rewarded by his being appointed Minister of State at the Department of Posts and Telegraphs after Haughey became Taoiseach. He held this position until Fianna Fáil's defeat at the 1981 general election—at which, after changes in constituency boundaries, he switched to the Galway West constituency.

He lost his Dáil seat there at the February 1982 general election, but was elected to the Seanad where he served until 1987. In an incident in 1982, Senator Killilea led some Workers' Party Teachtaí Dáil into the Dáil chamber through the press gallery, when all other entrances to the chamber had been locked due to the running of a Dáil vote, (nomination of Charles Haughey to the office of Taoiseach).^[4] After Ray MacSharry retired from the European Parliament in 1987, Killilea was appointed as his replacement in the Connacht–Ulster constituency. Killilea held the seat at the 1989 and 1994 European Parliament elections, and was elected as Quaestor by his fellow MEPs in 1996. He retired from politics at the 1999 European Parliament election.