Since the inception of the greenways concept, transportation has been one of its inherent qualities. Nevertheless, journal articles from the past three decades reported negligible active transportation (AT) impact of many greenway investments worldwide. Simultaneously, an international empirical evidence base of greenways usage for AT has not yet been established. Therefore, this research aimed to identify and analyze the influences on greenways usage for AT via a systematic review of published peer-reviewed journal articles from 1991 until 2021. The review used protocols of the PRISMA Statement in reporting and meta-analysis. Via two levels of screening criteria, results identified 162 articles that focused on greenway users and 27 (out of 162) articles that had AT as a main part of their study. The review specified patterns in the characteristics, perceptions, and travel behaviors of active commuters via greenways, which differed from other user types. Differences in use were also affected by weather and temporal factors, greenways’ location and characteristics, and contextual factors. A discussion of the findings identified four study types of greenway usage, highlighted methodological concerns of systematic reviews in this field, characterized transportation-led greenways, proposed a conceptual framework that illustrates where and when greenways would be considered routes for daily commutes, and suggested future work directions. These results improve the understanding of greenways usage, thereby informing their planning, design, and management to maximize their potential.