Contemporary planning systems are often described as “entrepreneurial”, marked by privatization and growing developer influence over public deliberative governance. This binary framing, however, overlooks the expanding role of planning consultants as intermediary professionals operating between public and private actors. Since the emergence of “consultocracy”, the use of consultants in governance has grown significantly, driven by new policy demands, austerity, technological change, and privatization. The increasing reliance on private professional expertise and accelerated modes of policy development has raised concerns about public deliberation and the legitimacy of planning expertise.

This paper presents a systematic literature review (N=70) synthesising emergent research on the roles and impacts of planning consultants in urban planning. The review identifies planning consultants as hybrid actors fulfilling overlapping roles: as advocates for development interests, advisors producing technical evidence for public authorities, and increasingly as scrutineers evaluating planning knowledge and processes. The literature also points to a shift from specialist “expert” roles towards broader, multidisciplinary and managerial forms of consultancy – and from disciplinary professionals to “midwives” of project realization. These roles position consultants centrally in the production, validation, and mobilisation of planning knowledge, while embedding them in tensions between neutrality, professional norms, and client service.

Across contexts, several recurring impacts emerge (N = 11). Consultant involvement is associated with the marketisation of planning practice, capacity substitution, and knowledge production increasingly shaped by client needs. Empirical studies also highlight depoliticisation and the neutralisation of participation through technocratic expertise, alongside mounting accountability challenges. Through “pay-for-priority” dynamics, consultants can shape agenda-setting and policy prioritisation. The paper concludes that planning consultants are key agents in the restructuring of urban governance, warranting further research beyond Anglophone contexts.