Statistics is an essential part of mathematics. It deals with the presentation, collection, organization, analysis and interpretation of data. In statistics, sampling theory refers to the survey method in which a particular group of people are chosen to represent the larger population. It is a very commonly used method in research and marketing. The different types of sampling methods are systematic sampling, cluster sampling, snowball sampling, minimax sampling, stratified sampling, theoretical sampling, etc. This textbook is a valuable compilation of topics, ranging from the basic to the most complex theories and principles in the field of statistics and sampling theory. It will serve as a valuable source of reference for those interested in this field.