International Conference on Statistics, Mathematics, Teaching, and Research (ICSMTR) 2021 is the 4th ICSMTR and the biennial event organized by the Department of Statistics and the Department of Mathematics, Faculty of Mathematics and Natural Sciences, Universitas Negeri Makassar. The conference provides a forum for discussion on improving the quality of research and publication by promoting cutting-edge methods of Statistics, Mathematics, Science, and Teaching. The conference program includes a keynote presentation, workshops, invited speakers, and parallel presentation sessions. Due to the Covid-19 outbreak, this conference has been successfully held virtual and non-virtual (for presenters or participants from Makassar with health protocol of Covid-19) on 9-10 October 2021 at the Faculty of Mathematics and Natural Sciences, UNM, Makassar Indonesia.The theme of this conference is “Optimizing Data Science to Reach Society 5.0 through High-Quality Research” with aims to increase collaboration between researchers from various universities and countries in the fields of Statistics, Mathematics, Science, and Teaching as well as to increase the number of researcher publications in journals or proceedings indexed by indexers with international reputations such as SCOPUS and Web of Science.We have 8 invited speakers and 84 presenters both from local and international presenters. The international presenters come from 10 countries namely Nigeria, Thailand, China, Taiwan, Australia, French, Morocco, Saudi Arabia, Malaysia, and Indonesia. The local presenters come from about 46 institutions/universities. The time spent delivering the talks by each invited speaker was 20-30 minutes following by a Question Answer (Q & A) Session for 30 minutes and 7- 10 minutes for each contribution talk. Around 280 participants attended the conference via zoom meeting.On behalf of the committee would like to deliver our highest appreciation to the Keynote Speaker, Rector of Universitas Negeri Makassar, Prof. Dr. H. Husain Syam, M. TP., IPU., ASEAN Eng. and all invited speakers who have been willing to spend their time to share their knowledge to all the participants of the 4th ICMSTR 2021. We would like thanks to sponsors and all the organizing committee for their hard work and effort in the accomplishment of this event. Finally, we would like also to thank the State University of Makassar, the Statistics higher education forum (FORSTAT), the Indonesian Statistics Association (ISI), and the Indonesian Mathematical Society (IndoMS) for their support.List of Steering Committee, International Scientific Committee, Committee, Executive Committee, Secretary, Treasurer, Reviewer, Administration Committee, Editing and Publication Committee, Program Committee, Logistic and Decoration Committee, Fund and Sponsorhip Committee are available in this pdf.