Beijing’s residential CO2 emissions have become the main growth point of CO2 emissions. However, the impact factors of the direct energy-related CO2 emissions from residents in Beijing have not been previously evaluated. This paper accessed the key factors that affect the residents’ CO2 emissions in Beijing from 1995 to 2015, using a newly built decomposition model with generalized Fisher index (GFI) and M-P model. The results were compared between urban and rural areas. Urban residential CO2 emissions did not change during 1995–1999 but then grew rapidly after 1999, while rural residential CO2 emissions fluctuated during the studied period. Increased per capita income is the most important pulling factor for the growth of residential CO2 emissions, while energy consumption intensity is a decisive factor in inhibiting residential CO2 emissions. Population size plays a pulling role in the growth of residential CO2 emissions. Energy structure exerts a role in inhibiting residential CO2 emissions, and its inhibition effect is stronger for urban residents. Average consumption propensity inhibits urban residential CO2 emissions but has little effect on rural residential CO2 emissions. The population migration from rural to urban areas in the urbanization process increases residential CO2 emissions. To reduce residential CO2 emissions, several recommendations have been proposed.