This is the peer reviewed version of the following article: Ralston, J. (2017). Islam as Christian Trope: The Place and Function of Islam in Reformed Dogmatic Theology. The Muslim World, 107(4), 754–776., which has been published in final form at https://doi.org/10.1111/muwo.12220. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.