Although many psychologists are interested in making the world a better place through their work, they are often unable to have the impact that they would like. Here, we suggest that both individuals and psychology as a field can better improve human welfare by incorporating ideas from effective altruism, a growing movement whose members aim to do the most good by using science and reason to inform their efforts. In this article, we first briefly introduce effective altruism and review important principles that can be applied to how psychologists approach their work, such as the importance, tractability, and neglectedness framework. We then review how effective altruism can inform individual psychologists’ choices. Finally, we close with a discussion of ideas for how psychology, as a field, can increase its positive impact. By applying insights from effective altruism to psychological science, we aim to integrate a new theoretical framework into psychological science, stimulate new areas of research, start a discussion on how psychology can maximize its impact, and inspire the psychology community to do the most good.