Illicit drug policy interventions cover treatment, law enforcement, prevention and harm reduction. This paper provides a comprehensive list across these sectors, of known drug policy interventions. One hundred and eight interventions were identified. With such a long and undifferentiated list of drug policy interventions, the ways in which these interventions are then coded and classified is also addressed. Ten different classification schemes are reviewed including summary information on the original sources and backgrounds to the schemes. The authors rated each of the policy interventions against the schemes. Those which proved useful in summarising illicit drug policy interventions included the four pillars approach, the UNODC classification, the demand, supply and harm reduction paradigm, the public health model and the policy instruments model. The list of 108 policy interventions will be of use to policy makers, researchers and practitioners in appreciating the array of drug policy options, and could be used in reviews of policy or practice. The classification schemes reveal the different ways in which drug policy interventions can be clustered and described to different audiences.