The 3rd International Conference on Statistics: Theory and Applications (ICSTA’21) aims to become the leading annual conference in fields related to Statistics: Theory and Applications. The goal of ICSTA’21 is to gather scholars from all over the world to present advances in the relevant fields and to foster an environment conducive to exchanging ideas and information. This conference will also provide an ideal environment to develop new collaborations and meet experts on the fundamentals, applications, and products of the mentioned fields. ICSTA is an acronym for International Conference on Statistics: Theory and Applications.