Lorcan Allen (born 27 March 1940) is an Irish farmer and former Fianna Fáil politician.
Allen was elected to Dáil Éireann as a Fianna Fáil Teachta Dála (TD) for the Wexford constituency at the 1961 general election. Aged 21 years and 6 months at the time, he is the third youngest ever TD. He held his seat in 6 succeeding general elections until his defeat at the November 1982 general election. He also unsuccessfully contested the next three general elections.
When Charles Haughey appointed his first Government in December 1979, Allen became a Minister of State, appointed to the Department of Agriculture, a position he retained in the short-serving 1982 Government.
Allen lost his county council seat at the 2009 local elections, but retained his Gorey Town Council seat.