E-government has become an integral component of civil society, supporting the provision of quality public services and facilitating public administration. As new technological innovations emerge, e-government research continues to evolve. In recent years, researchers have investigated the potential and impact of new digital innovations in public administration, citizen participation, service delivery, and environmental sustainability. To better understand how digital innovation can be utilized in e-government, scholars have been testing and applying theories to study interesting digital government phenomena and artifacts. This study synthesizes the theoretical foundation of e-government research. Additionally, it provides a multifaceted analysis of the identified theories. Our findings contribute to a cumulative knowledge base of e-government theories to inform further e-government research and designs.