List of songs that reached number one on the Irish Singles Chart
Below are to lists showing the songs that have topped the chart. Dates shown represent "week-ending" IRMA issue dates. Prior to 1992, the Irish singles chart was compiled from trade shipments from the labels to record stores, rather than on consumer sales, and were first broadcast on RTÉ on 1 October 1962. Before this charts had been printed in the Evening Herald newspaper, but are under debate as to whether they are official or not, note that the singles mentioned below are only those that come from the 'official chart', and that no information is given for any number 1's before October 1, 1962.
In 1992, the singles chart became based on consumer sales after IFPI and the Irish Recorded Music Association granted a contract to Gallup, a market research company. Gallup installed Epson PX-4 devices in sixty record stores to collect singles sales data. In 1996, Chart-Track was formed as a result of a management buy-out from Gallup. Also in 1996, with the development of technology, EPOS systems were installed in multiple music retail stores. The EPOS systems allowed for the collection of more accurate sales information. Currently, Chart-Track collects data daily from major record stores such as HMV and Tower Records, as well as over forty Independent retailers. In total, data from over three-hundred and eighty stores are collected each week. The singles chart is compiled over seven days and released every Friday at noon by the IRMA, while Midweek Charts are produced daily, but only released to IRMA members.