Public administration as a body of knowledge and subject of study continues to shift from a political science-dominated paradigm to an interdisciplinary mix of theoretical contributions from all social science fields. Therefore, understanding of the theories, concepts, and ideas of social science disciplines is very crucial to understanding the theory and practice of modern public administration. This paper examines the close propinquity between public administration and social science disciplines. In order to carry out this work, data were obtained largely from secondary sources from books, articles journals, Nigerian constitution, published and unpublished materials available as well as internet sources and it was analysed through discourse analyses from different perspectives of disciplinary evolution, development, scope, boundary, research, theory and practice, interrelationship among social sciences, It has been discovered inter-alia that the study and practice of public administration has been significantly influenced and shaped by various social science disciplines like political science, law, sociology, psychology, economics as it incorporates various ideas, concepts and principles in terms of policy formulation, implementation, evaluation as well as general human resource management. The paper recommends that in view of the increasing concern for effectiveness and efficiency in the act of administration, good understanding of the various social science disciplines is very desideratum for administrators especially with expanding demand for public policy reforms related to satisfaction of needs and aspiration of the people. Public administrators should be more proactive pursuit of innovation and breakthroughs in formulation and implementation of policies and programmes for the public interest.