Background: Anti-cancer therapies increase risk for cognitive impairment. Physical activity (PA) is globally recognized as an effective strategy to mitigate adverse effects associated with anti-cancer therapies. To inform implementation/future research, we performed a scoping review of studies on PA and cognition among persons with cancer to (1) understand evidence regarding the associations between PA and cognitive measures, and (2) identify gaps requiring further research. Methods: A protocol was published on the Open Science Framework. MEDLINE, Embase, PsycInfo, and CINAHL databases were searched using a sensitive search strategy in 02/2021 and updated in 03/2022. Two reviewers independently screened titles/abstracts and full-texts. After extracting, verifying, and summarizing data from eligible full-texts, findings were classified as positive, negative, or inconclusive. Results: Searches returned 4147 records; 80 were eligible. Included articles were largely published in the past five years (66.3%), by authors in high-income countries (91.3%), and experimental in nature (66.3%); fewer were cross-sectional (23.8%) or longitudinal (10%). Of the quantitative studies, 86.1% reported overall positive findings (i.e., supporting PA to promote cognition or vice versa), while 5.1% were negative, and 8.9% inconclusive. Only two (2.5%) studies presented qualitative data; one supported a positive association. Studies predominantly focused on persons with breast cancer (51.3%) and individuals post-treatment (68.8%). Representation of diverse samples, young samples, and large-scale studies with long-term follow-up was lacking. Conclusions: A modest but growing evidence-base suggests PA may improve cognition in persons with cancer. Large-scale studies with long-term follow-up and comprehensive PA and cognitive interventions/measures are needed, especially with underrepresented groups.