An Post National Lottery Company (Irish Comhlacht Chrannchur Náisiúnta An Post) is the company which has the licence of "the National Lottery" (Irish: "an Crannchur Náisiúnta") of the Republic of Ireland. The company was founded by its parent company An Post under a licence issued under the National Lottery Act, 1986 by the Minister for Finance for a lottery. The ownership of the company is between An Post and the Minister of Finance; it is split 80 to 20 percent respectively. The "National Lottery Fund" is a account kept at the Central Bank of Ireland and this is used to fufil the primary objective of the company which is the funding of "good causes", surpluses are paid to the account annually and distributed by the Minister.

The Irish Sweepstakes and Rehab Lotteries also entered the tender process in 1986, but were unsuccessful, and An Post has retained the licence at every bid process since and will retain it until December 31, 2008 unless the Minister for Finance revokes the current licence before that time. The National Lottery commenced on March 28, 1987 with scratch cards and on April 16, 1988 it held the first live draw "the Lotto", which is currently run twice weekly. Since that time it has expanded its games and revenue and also funds television game shows, most notably Winning Streak. It has also been part of the Euromillions lottery since 2004.

In its most recent financial results (2004) the National Lottery contributed € 235.9 million to good causes under the broad headings of Youth, Sport, Recreation & Amenities (139.0), Health & Welfare (65.1), Arts, Culture & National Heritage (27.9), Irish Language (3.9).

Players choose 6 numbers out of a possible 42, with 6 numbers plus one bonus number. A player choosing all 6 correct numbers (at a probability of 1 in 5,245,786) wins the jackpot, which is always at least €1,500,000. 5 plus the bonus wins typically about €25,000, while smaller prizes exist for 5, 4+bonus, 4 and 3+bonus.