The East Bay is the eastern region of the San Francisco Bay Area and includes cities along the eastern shores of the San Francisco Bay and San Pablo Bay. The region has grown to include inland communities in Alameda and Contra Costa counties. With a population of roughly 2.8 million in 2024, it is the most populous subregion in the Bay Area, co…The East Bay is the eastern region of the San Francisco Bay Area and includes cities along the eastern shores of the San Francisco Bay and San Pablo Bay. The region has grown to include inland communities in Alameda and Contra Costa counties. With a population of roughly 2.8 million in 2024, it is the most populous subregion in the Bay Area, containing the second- and third-most populous Bay Area counties of Alameda and Contra Costa.