The purpose of this chapter is to review theoretical and empirical developments in the scientific understanding of semantic memory, semantic priming, and repetition priming. We begin by summarizing the classical models of semantic memory and the major empirical findings that were used to test those models. We also summarize two contemporary models of semantic memory, distributed network models and high‐dimensional spatial models. In the second section of the chapter, we examine semantic priming. We review the most influential models of semantic priming; viz., spreading‐activation, compound‐cue, and distributed‐network models. We then summarize the major empirical findings on semantic priming, focusing in particular on issues that have turned out to be important for testing models of semantic priming and on findings published since Neely's (1991) review. In the third section, we examine repetition priming. We summarize the most influential models of repetition priming, such as the logogen model, the counter model, instance theory, and distributed network models. We then review some of the major issues and findings on repetition priming. We close the chapter with a summary of our conclusions and a discussion of promising directions for future research.