While Irish creameries today are popu larly associated wi th co-operative ownership, in fact over the first forty years of the development of the creamery system in Ireland, the majority of creameries were in private ownersh ip. These so-called "proprietary" creameries are the main focus of this chapter, which is structured as follows. Init ially, the traditional method of making butter on farms is described briefly and compared with the new creamery technology. This is followed by a general account of the spread of the creamery system in Ire land. The chapter then provides a profi le of the proprietary creamery sector, focu si ng firstly on some of the individual entrepreneurs who played key roles in the development of the sector and then on the corporate groupings (bot h Irish and Bri tish owned) which came to dominate the sector. The chapter concludes with an account of major legislative and organisational changes instigated by the Irish Free Sta te Government in the 1920s which elimi nated the proprietary sector from the Irish creamery industry, thereby leaving it almost completely cooperatively-owned.