National Museum of Ireland – Decorative Arts and History, National museum for decorative arts and history in County Dublin, Ireland.

The National Museum of Ireland – Decorative Arts and History is a museum housed in a former military complex on the north bank of the River Liffey in Dublin, displaying objects ranging from ceramics and glassware to furniture, textiles, and military items. The collections are arranged across several rooms and buildings within the old barracks complex.

The Art and Industrial Division of the Dublin Museum of Science and Art was founded in 1877, and by 1889 it held 10,372 objects stored at Kildare Street. After independence in 1922 it took on Irish military and political collecting, mounting its first Easter Rising exhibition in 1932. The government decided in December 1988 to close Collins Barracks as a military facility, and in 1993 agreed that the National Museum of Ireland would take over the site.

The museum's name in Irish is Ard-Mhúsaem na hÉireann – Na hEalaíona Maisiúla ⁊ Stair. Its Easter Week Collection began with a 1932 exhibition on the Easter Rising at Kildare Street, the museum's first contemporary and thematic collection, built largely from objects donated or loaned by members of the public. From 1908, under director Count George Noble Plunkett, collecting focused on objects described as "distinctively Irish".

The museum occupies the former Collins Barracks in Arbour Hill, on the north bank of the Liffey west of the city centre. It is one of four NMI branches in Dublin, and entry to all four museums is free. The Luas line was built to link the site with the city and with the Irish Museum of Modern Art in Kilmainham.

The museum's building, Collins Barracks, was closed as a military facility by the Irish government in December 1988, and in 1993 an agreement was reached for the National Museum of Ireland to take possession of the site. The move was part of the Historic Area Rejuvenation Project, a plan to renew 270 acres between Collins Barracks and O'Connell Street, with the museum as the centrepiece of a new museum quarter.