This article explores the relationship between knowledge and sustainable placemaking. Distinguishing between “expert knowledge” and “local knowledge,” it first problematizes expert knowledge, and then traces the local knowledge approach to placemaking. The widening gap between expert and local knowledge prompts understanding their sources and modes of knowing. By viewing place as an organization this article draws from Nonaka's (1994) distinctions of four modes of knowledge creation in an organization, and explores the commonalities between the two. The analogy between place and organization helps gain new insights from the organizational theory literature which links processed information to knowledge creation. Seeking similarities between place and organization arises from how individuals in organizations and places process information to solve problems. Critically examining local knowledge questions the presupposition of a fixed, static mode of knowing, and helps incorporate a range of activities and knowhow associated with different stages of placemaking. The study suggests that local knowledge converts existing knowledge into four types of new knowledge during the placemaking process. Furthermore, compared to the top-down nature of expert knowledge which mainly adheres to the principles of scientific rationality for grand planning and problem solving, the local knowledge approach to placemaking is bottom-up, fosters piecemeal growth, and thus is more adaptable and sustainable. Promoting (social) sustainability through knowledge conversion (i.e., converting tacit knowledge into explicit knowledge and vice versa), social interaction and self-help characterize placemaking in informal settlements.