A workshop held at the University of Cambridge in May 2017 brought developers, researchers, knowledge brokers, and users together to discuss user-centred design of decision support tools. Decision support tools are designed to take users through logical decision steps towards an evidence-informed final decision. Although they may exist in different forms, including on paper, decision support tools are generally considered to be computer- (online, software) or app-based. Studies have illustrated the potential value of decision support tools for conservation, and there are several papers describing the design of individual tools. Rather less attention, however, has been placed on the desirable characteristics for use, and even less on whether tools are actually being used in practice. This is concerning because if tools are not used by their intended end user, for example a policy-maker or practitioner, then its design will have wasted resources. Based on an analysis of papers on tool use in conservation, there is a lack of social science research on improving design, and relatively few examples where users have been incorporated into the design process. Evidence from other disciplines, particularly human-computer interaction research, illustrates that involving users throughout the design of decision support tools increases the relevance, usability, and impact of systems. User-centred design of tools is, however, seldom mentioned in the conservation literature. The workshop started the necessary process of bringing together developers and users to share knowledge about how to conduct good user-centred design of decision support tools. This will help to ensure that tools are usable and make an impact in conservation policy and practice.