Field theories have been central to physics over the last 150 years, and there are several theories in contemporary physics in which physical fields play key causal and explanatory roles. This paper proposes a novel field trope-bundle (FTB) ontology on which fields are composed of bundles of particularized property instances, called tropes and goes on to describe some virtues of this ontology. It begins with a critical examination of the dominant view about the ontology of fields, that fields are properties (...) of a substantial substratum. (shrink)