<p>Optimizing thermal management systems (TMS) in electric buses (E-buses), including HVAC systems, battery thermal management, motor, and power electronics systems, can improve their energy efficiency, cabin thermal performance, and overall mileage throughout their battery life. Although integrated TMS have been studied in previous research, performance optimization in their cabin thermal management systems (CTMS) is often overlooked and has not been thoroughly investigated. To fill this research gap, this study transfers knowledge from a building energy modeling approach to assess CTMS electricity consumption flexibility, a fundamental step toward future TMS designs. Three pioneering contributions of this paper are: (1) creating a physics-based E-bus prototypical CTMS model, (2) determining the distributions of four key factors (i.e., air change per hour (ACH), indoor air temperature setpoints, number of people, and ambient environment) to affect the flexibility of CTMS electricity consumption in E-buses, and (3) quantifying the impacts of these key factors on the flexibility through four typical cities in the United States with various climate features (i.e., Miami, FL; Phoenix, AZ; Baltimore, MD; and Helena, MT). The results reveal that changing the number of occupants significantly impacts CTMS electricity consumption, with the largest variation (up to ± 50%) observed in Baltimore (mild and humid climate) during cooling days. In heating days, ACH is the dominant factor influencing electricity consumption in cold climates, with a magnitude similar to that of other factors. Conversely, the indoor air temperature setpoint in heating days contributes the least to electricity consumption flexibility. This study provides a foundation for improving the future energy efficiency of CTMS in E-buses by highlighting cabin-specific thermal dynamics.</p>