The importance of ‘set and setting’ for influencing psychedelic drug experiences is widely recognized. Indeed, ‘drug’, ‘set’ and ‘setting’ are understood as having complex and interactive relationships. However, there are notable shortcomings in how ‘setting’ is operationalized and reported in psychedelic science to date, hindering the field’s integrity and advancement. To address this gap, we initiated ‘The Delphi Study on Setting’, prompting over 70 psychedelic experts with the following research question: how can setting be effectively and accurately reported in psychedelic clinical trials? Our goal was to formulate a set of reporting guidelines for ‘setting’ variables in psychedelic clinical trials that were derived from diverse voices, parsimonious, and feasible to implement. We employed the Delphi Consensus Method – a recognized approach for reaching expert consensus on complex topics through an iterative, survey-driven, and anonymous process. Throughout four iterative rounds, experts listed hundreds of essential ‘setting’ variables to report that were distilled into a set of 49 items, which were then rated according to their importance, debated, and reviewed. This process produced a list of 30 items reaching final consensus, meaning they were rated as “important” by at least 70% of the experts. These items now lie at the core of ‘The Delphi Guidelines on Setting Reporting in Psychedelic Trials’. In pursuit of advancing our collective understanding of drug-context interactions, we propose these guidelines – rated favourably by 95% of the involved experts – as a new standard for designing and reporting psychedelic research trials.