Background: Remote monitoring of daily activity using wearable activity monitors (“wearables”) (e.g., Fitbits) provides an unintrusive method to obtain continuous, objective physical activity (PA) and sleep data outside the clinical setting. Despite their potential for improving PA assessment for cancer survivors, there is currently limited information on how wearables are being used in PCa survivors. Thus, we reviewed the literature to understand how wearables are being integrated into research and interventional studies conducted in PCa survivors. Methods: We searched PubMed, CENTRAL, and Clinicaltrials.gov for randomized controlled trials (RCTs) and observational studies that involve commercially available wearables in PCa survivors, published between 2012 and 2022. Upon screening and full-text review by two independent reviewers, data were extracted from eligible studies, including study and patient characteristics, details on study interventions and outcomes, and purpose of device use. Baseline PA data were abstracted from articles with available quantitative data, including step counts, time spent in moderate-to-vigorous physical activity (MVPA), and sleep duration, and included in a quantitative analysis. Results: Eighty studies were screened and 17 studies met eligibility criteria and were included in this review (8 RCTs; 9 observational), with a total sample size of 1,148 PCa survivors (median age 66 years, range 39-84). Wearables used included: Fitbit: (47%), pedometer (18%), smartphone (6%), Jawbone (6%), and heart rate monitor (6%). Most studies (71%) involved individual or group-based exercise interventions that were either gym-based supervised by an exercise physiologist or home-based (online web-based delivery or written recommendations), as well as remotely delivered behavioral interventions. One study compared objective (actigraphy) and subjective sleep quality measures and one was a validation study comparing Fitbit to the ActiGraph accelerometer. Study durations ranged from 1-48 weeks with median reported adherence to wearing the device of 79.5% (range 63-100%). PA data, as measured with wearables, were available in 13 studies and summarized. Conclusions: Wearables are increasingly being used to assess daily activity and monitor adherence to exercise interventions in PCa survivors. Findings suggest wearables are feasible for use in this population with high levels of adherence. Wearables can provide added value to PA and functional assessment, although more research is needed to understand how wearables can be integrated into routine patient care or used as means to track or deliver tailored interventions for PCa survivors.