Commons traditionally refer to shared natural resources that are at risk of being depleted or even destroyed. The rules established by commoners offer a way to manage such scarce resources. Through a series of projects on national eHealth patient health records, we have identified another type of shared resources – semantic resources – that would benefit from commons-based governance. Semantic resources are standardised definitions of data that ensure a common understanding of data during processes of data sharing between different actors and systems. In this paper, we first use commons as a lens to explore shared semantic resources and the governance challenges associated with them (e.g. lack of cross-cutting support across many projects). This leads to a better understanding of (1) shared semantic resources as global commons, (2) the relationship between the global and local levels of semantic resource governance and, by observing traces of commoning at the local level, (3) the role of commoning as a crucial concept in the context of semantic interoperability. Second, we introduce the notion of semantic commons to address the governance problems of semantic resources that needs to be continuous and sustainable. In addition, we also contribute to the commons literature by proposing a new area of research for commons scholars. We identify semantic resources in healthcare as an interesting and important type of resource that offers a new perspective on the dynamics of the relationship between global and local commons. We also identify a central role for commoning in healthcare in general as well as in the governance of semantic resources there.