A mixed methods rationale is a justification researchers use to substantiate their application of mixed methods research. Identifying a clear mixed methods rationale enhances the credibility and rigor of a mixed methods study as well as advocate for and explain this methodology to readers. The purpose of this article is to provide guidance on how to effectively communicate and apply a mixed methods rationale. First, I describe how mixed methods researchers subtly and explicitly refer to their rationales and where they do this in their writing. Second, I detail how researchers demonstrate their rationale in several features of mixed methods research: the mixed methods design, integration, presentation of findings, and comparing the study to other published literature. I draw from literature in the field of mixed methods as well as example published studies the demonstrate a wide range of mixed methods rationales. I conclude with several recommendations and areas of further exploration in the use of mixed methods rationales. (PsycInfo Database Record (c) 2023 APA, all rights reserved).