Since the launch of the first All India Coordinated Research Project (AICRP) in maize in 1957, the public research in crop improvement, especially under the Indian Council of Agricultural Research (ICAR), has come a long way in independent India, which played a vital role in developing the Indian seed sector. The focus of these coordinated projects was initially on development and evaluation of open pollinated varieties (OPVs) of some of the major field crops. However, after the happening of the Green Revolution, crop improvement programs in wheat and rice occupied the center stage in the 1960s and 1970s followed by others. Impact of AICRPs in the release of high-yielding varieties (HYVs) in self-pollinated crops, and OPVs and hybrids in cross-pollinated crops resulted in steady increase in food grain production. Thereafter, the scope of AICRPs became much wider. All public research institutions within the National Agriculture Research System (NARS) intensified their crop improvement programs. Taking into consideration the development of improved crop varieties, a strong organized seed supply system was required to reach the benefits of the crop improvement to farmers. Thus, National Seeds Corporation (NSC) was established in 1963. This was followed by the establishment of Tarai Development Corporation (TDC) and State Farms Corporation of India (SFCI) owned by several State Seeds Corporations in 1969. Together, these public sector organizations provided yeoman’s service to the development of Indian agriculture. Subsequently, a number of state seed corporations were established in 70s and 80s under the National Seeds Project (NSP). Meanwhile, the private seed sector also emerged and started growing steadily. Thus, a continuum was built that served as a medium for supply of quality seeds from breeders to farmers. Although the private sector also engaged in crop improvement research, it began expanding more vigorously after late 80s, being encouraged by the government’s New Policy on Seed Development (NPSD) in 1988. Private sector’s primary focus was on high-value seeds of hybrids of vegetables and selected field crops. Subsequently, genetically modified (GM) crop varieties, especially Bt cotton, received its highest priority. The public research, on the other hand, began putting more attention on application of precise molecular tools for breeding superior cultivars possessing traits of economic importance, for example, tolerance to biotic and abiotic stresses, and improvement of nutritional quality in major food grain crops. Public sector crop improvement research remains as much relevant today for the nation’s food and nutrition security as it was in the 50s. In accordance with the liberal policies of ICAR, seeds of the varieties and of the parental lines of hybrids developed under the public research are made available for multiplication and sale to both public and private sector seed-producing companies at reasonable prices. Latest varieties of the public research system having high market potential are also licensed under proper legal agreement to commercial seed growers. Public research institutions are continuing to play an important role in improvising the informal seed sector through Farmers’ Participatory Seed Production (FPSP) programs. Indian public research and its complementarity with the private sector provides a unique model of a vibrant seed system. This chapter focuses on the role of public research in seed sector development with particular reference to the contributions of ICAR-Indian Agricultural Research Institute (IARI)—a premier agricultural research institution under ICAR.