Locus of Control (LOC) is a general term used in social and educational psychology to refer to the perceived source of control for behavioural outcomes. Since the 1980s, various instruments have been developed to measure this construct in relation to pro-environmental behaviours and action. In this article, we revisit the value of this construct and its measurement to offer a critical analysis of the psychometric properties and instrument construction approach of eight publicly available Environmental Locus of Control (ELOC) instruments. Our analysis focuses on both the robustness of their instrumentation alongside the continued relevance of these measures to diverse audiences in light of various methodological advances. Findings suggest that while the theories and tools available for developing and validating ELOC have become more sophisticated, even the most recent ELOC instruments still exhibit key limitations, particularly in relation to content and construct validity. In light of this, we propose a series of considerations for developing more rigorous ELOC instruments to help improve future measurement of action and self-determined behaviour.