Emile Durkheim, but saint simon coined the term sociology I think. You also have to consider the contributions of Max Weber, C Wright Mills and Karl Marx. Talcott Parsons is a famous structural functionalist, who supported the Nazis. August Comte contributed to social science and positivism. George Zimmel is also a founding father of sociology,, but the most influential in all social theory and critical social theory is Karl marx with his theory of alienation laid out in the Philosophical Manuscipts of 1844