This book is an exposition of some fundamental concepts of Fuzzy Algebra, Fuzzy Topology along with applications of Fuzzy Set Theory in diverse field of scientific knowledge. Today in almost all disciplines of science, engineering and technology, the theory of Fuzzy Sets has become an indispensable part of the curriculum. In fact, Fuzzy Set Theory (FST) provides language for almost all disciplines in contemporary mathematics in much the same way as mathematics does for many sciences. The book first provides exposure to the concepts of fuzzy subgroupoids, fuzzy subgroups, fuzzy level subgroups, fuzzy normal subgroups, fuzzy ring, fuzzy ideal, fuzzy field, fuzzy linear spaces, geometrical sets in a linear space, fuzzy module. Secondly, topological & algebraic topological linear spaces has been dealt with. Finally, the applicational aspects of Fuzzy Set Theory (FST) to two different areas of human knowledge such as sports (Cricket scores) and medicine (detection of blood sugar in human beings) are in-corporated.