伦斯特省 （Leinster；爱尔兰语：Laighin/ Laigin），是爱尔兰四个历史省份之一，位于爱尔兰岛东部。下分12郡，当中包括了原来也是一个省的米斯郡和西米斯郡。

主要市区按大小顺序（2006年人口普查数据，城市地区拥有超过10,000名居民）：

根据的CSO区域的收入报告，2004年的伦斯特省的国内生产总值预计将超过75亿欧元。

Leinster (/ˈlɛnstər/ — Irish:Laighin / Cúige Laighean — pronounced [ˈl̪ˠaːjɪnʲ]) is one of the Provinces of Ireland situated in the east of Ireland. It comprises the ancient Kingdoms of Mide, Osraige and Leinster. Following the 12th-century Norman invasion of Ireland, the historic fifths of Leinster and Mide gradually merged, mainly due to the impact of the Pale, which straddled both, thereby forming the present-day province of Leinster. The ancient kingdoms were shired into a number of counties for administrative and judicial purposes. In later centuries, local government legislation has seen further sub-division of the historic counties.