This paper attempts to locate, within an actualist ontology, truthmakers for modal truths: truths of the form or . In Sect. 1 I motivate the demand for substantial truthmakers for modal truths. In Sect. 2 I criticise Armstrong’s account of truthmakers for modal truths. In Sect. 3 I examine essentialism and defend an account of what makes essentialist attributions true, but I argue that this does not solve the problem of modal truth in general. In Sect. 4 I discuss, and dismiss, a theistic account of the source of modal truth proposed by Alexander Pruss. In Sect. 5 I offer a means of (dis)solving the problem.
