The purpose of this article was to explore the extent to which nonlinguistic cognitive factors demonstrate a relationship with aphasia treatment outcomes. To that end, we conducted a scoping review to broadly characterize the state of the literature related to this topic. Methods: Reporting guidelines from the PRISMA extension for scoping reviews were used to conduct our study, which queried two common databases used in the health science literature, PubMed and Web of Science. Search terms and eligibility criteria are provided. Results are organized by the four nonlinguistic domains of cognition explored across the included studies (i.e., attention, memory, executive functioning, and visuospatial skills). Results: Of 949 unique articles identified from our database searches, 17 articles with 18 distinct studies were included in the final scoping review. Notably, most studies included in the scoping review targeted impairment-based aphasia treatments. Most studies also examined multiple domains of nonlinguistic cognition. A relationship between cognition and poststroke aphasia therapy outcomes was identified in nine of 15 studies addressing executive functioning, four of nine studies examining memory, four of eight studies examining visuospatial skills, and two of five studies exploring attention. Discussion: The results among included studies were mixed, with few discernible patterns within each of the four cognitive domains, though it appears that the influence of nonlinguistic cognition may depend on the timing (i.e., immediate vs. delayed post-treatment) and type (i.e., trained vs. untrained, generalized) of aphasia therapy outcomes. Future study designs should address maintenance, by including outcome measures at follow-up, and generalization, by including measures of performance on either untrained stimuli or trained stimuli in untrained contexts. Future work should also strive for larger sample sizes, perhaps through collaborations, or prioritize replicability to produce more reliable conclusions.