Although 'psychology' does not constitute a distinct sub-division of Epicurean theory, the term can be used to refer to a number of well-marked topics in their philosophical framework. These include (1) the bodily nature of the psyche, (2) the atomic composition of the psyche, and (3) links between psychological functions and the structure of the body. These topics fall, broadly, under 'physics' in Epicurean philosophy. However, the bodily and atomic nature of the psyche also has implications for Epicurean ethics, implications that can also be seen as part of their thinking about psychology. These implications include (4) the capacity of the psyche, in human beings, for the development of agency and responsibility, and (5) the mortal nature of the psyche. Also relevant is (6) Epicurean use of psychological language in ethical contexts, often without explicit reference to the bodily or atomic nature of the psyche, and (7) the psychological assumptions underlying the Epicurean therapy of beliefs and emotions. The focus here is on the first four topics, illustrated by reference to certain key sources, and on the issue of how to understand the theory of psyche-body relations implied in these ideas (Sections II-V). However, there is briefer comment on the latter three topics, indicating how the conception of psychology involved in those topics depends on, or is at least compatible with, Epicurean thinking about the psyche as bodily (Section VI).