The R Project for statistical computing (R) is a programming language and environment for statistics and graphing. Another commonly used programming language for statistics and data mining is Python. Both Python and R are easy to learn. If the primary purpose is statistical analysis, then R is usually preferred.Why learn/teach R? One of the major reasons why R is becoming more popular (TIOBE,2018) is that it is an open-source (i.e. free) software. Also, when dealing with a large number of variables, multiple datasets, and large samples, R is also a more efficient tool than traditional drop-down menu software such as SPSS. Finally, R programming is now very easy to use with the development of helpful packages.This open text will introduce R packages and step-by-step codes for conducting common statistical analyses in psychological research and classrooms. Funding acknowledgment: The author would like to thank the Society for the Teaching of Psychology (STP), American Psychological Association Division 2 Instructional Resource Award for their generous support of this project. This resource is licensed under the Creative Commons Attribution-ShareAlike4.0 International license (CC BY-SA4.0)