This article traces the spatially grounded operation of ‘medical sovereignty' by reading property alongside medical practice and regulation in a settler colonial city. It does so through the lens of the Antipodean life of one Canton-born doctor, James Lamsey, who was a prolific proprietor in the regional Australian city of Bendigo and used his interlinked proprietorial and medical powers to mediate between the Bendigo Chinese community and white settlers and doctors. Reading medical power through the lens of Lamsey’s life, shaped, as it was, by European-made laws, shows how settler medical sovereignty was enacted in a dynamic relation with Chinese medical sovereignty, performed here in the urban context of Bendigo, on unceded Indigenous Dja Dja Wurrung land. With support from the common law system, health-related boards were, in the late nineteenth century, intensifying a settler sovereignty, where board members and doctors practised increasingly exclusive forms of discretionary power and exercised the right to exclude non-white people from membership. At the same time, Lamsey was enacting a diasporic medical sovereignty that drew on Chinese imperial and British colonial authority. He leveraged his medical sovereignty towards promoting collective Chinese entitlements to health and to counter the exclusions of a whitening settler sovereignty.