The Anthem Companion to Harold Garfinkel brings together leading scholars and upcoming researchers in contemporary ethnomethodology to bring out the experimental character of Garfinkel’s legacy in the social sciences and beyond. Therefore, the Companion takes its cue from Garfinkel’s noted breaching experiments, enabling the reflexive investigation of trust conditions in situ, and asks how this research interest has been productively pursued and distinctively rearticulated, both within and beyond Garfinkel’s oeuvre. Whilst Garfinkel’s experimental legacy is often acknowledged, no systematic introduction to its distinctive outlook, tension-riddled diversification, and heuristic interest(s) is available to date. The Anthem Companion to Harold Garfinkel both fills and reflects upon that gap in the literature, thereby articulating ethnomethodology’s experimental outlook, if not recasting its current research directions.