The concept of public interest legitimises the planning profession, provides a foundational principle, and serves as an ethical norm for planners. However, critical discourses highlight the problems of the assumptions underlying the notion of public interest in spatial planning. Using an explorative literature review approach, the article aims to analyse various interpretations and applications of public interest in spatial planning. The literature search process, conducted between August and November 2023, targeted journal articles and books published in English and focused on the online databases of Academic Search Premier, Scopus, and Google Scholar. The final selected literature comprised 71 sources. The literature showed that diverse conceptualisations of public interest complicate the ways spatial planners and authorities incorporate it in planning tools, processes, and products. This article concludes by arguing that the prospects of achieving a single definition of the public interest concept are slim and may not be necessary given the heterogeneous conceptualisation and the multiple operational contexts of public interest. The article recommends the development of context-based analytical frameworks to establish linkages that would lead towards the equitable inclusion of public interest in spatial planning.