Acceptance and Commitment Therapy (ACT) is an evidence-based intervention based on the counterintuitive idea that the road to well-being begins with accepting our painful thoughts and uncomfortable feelings, rather than trying to change them. It cautions against seeing positive mental health as solely the eradication of distress and instead stresses the importance of clarity about life values to help someone to guide their life. For ACT practitioners, it may be easy to adopt the basic principles of ACT, but it generally takes at least two or three years of ongoing study and practice to become truly fluent in the model. This chapter aims to offer an introduction to anyone intending to progress as an ACT therapist by providing an overview of key ideas that underpin the therapy, together with practical suggestions of how to take the next steps.