Recent advances in genetics, and new applications of evolutionary biology, are transforming psychology and psychiatry. The purpose of this article is to review and synthesize the progress in these two areas that is most salient to the practice of clinical psychology. First, I describe how the results of genome-wide studies have elucidated the genetic architectures of psychiatric disorders. These genetic results can be applied to generate polygenic risk scores, identify rare causal mutations, evaluate gene by environment interactions, and help determine the specific causes of psychiatric disorders for each individual, all of which can help to guide therapies and treatments. Second, I explain how evolutionary theory, applied to human development, the human psyche, and mental disorders, leads to novel insights relevant to therapy. Evolutionary thinking for psychiatry and psychology is consilient with contemporary schools of thought in clinical psychology, but also provides novel, non-intuitive, and clinically-useful insights. Effects of the genome in development, and functioning of the adult psyche, are both usefully conceived as dynamical, non-linear systems, regulated by feedbacks, that can become disordered in predictable yet individualistic ways. The merging of genetic, neurological, psychological, and evolutionary approaches is set to transform clinical psychology and psychiatry, but requires increased emphasis on cross-disciplinary thinking and research.Copyright © 2020 Elsevier Ltd. All rights reserved.