Taxus chinensis var. mairei is an endangered tree species endemic to China; it has important ornamental, timber, and medicinal value. In this work, based on a MaxEnt model, the Jiangnan hilly region was used as the study area, and geographic, climatic, soil, and vegetation data were synthesized to simulate the present area of suitable habitat for T. chinensis; the key environmental factors that constrain its habitat expansion were also explored. Additionally, the potential future distribution of this species under different climate-change scenarios was predicted. The results showed that the six variables making the highest contribution to T. chinensis habitat suitability were the precipitation of the warmest quarter (14.2%), precipitation seasonality variation coefficient (9.1%), aspect (8.2%), altitude (8%), maximum temperature of the warmest month (7.4%), and base saturation (6.6%). Ideal areas have middle elevations, northeastern or northwestern slopes, warmest quarterly precipitation of 508.3–629.2 mm, maximum temperature in the warmest month of 34.6–35.9 °C, and relatively moist soil. The current area of suitable habitat is 6.09 × 105 km2, of which the area of high suitability is 7.56 × 104 km2; this is mainly concentrated in the southwestern part of Hunan, the southwestern part of Jiangxi Province, and the northern part of Zhejiang. Under the SSP2-4.5 climate scenario, the area of high habitat suitability increases; under both the SSP1-2.6 and SSP5-8.5 climate scenarios, the suitable habitat area expands similarly. The direction of the center-of-mass migration of T. chinensis under different climate scenarios is somewhat different from that caused by the uncertainty of human activities and climate warming. This paper clarifies the distribution of suitable habitat and future potential for T. chinensis in the Jiangnan hilly region, providing a theoretical basis for habitat management of this species.