Utilizing the Technology-Organization-Environment (TOE) theory and the literature on citizen engagement (or participation), we formulated a multiple-mediation model, examining (1) the contextual antecedents of e-participation and e-government maturity; and (2) the mediating role of e-participation (in form of e-information sharing, e-consultation, and e-decision-making) on the relationships between the TOE contextual factors and e-government maturity. Based on archival data from 187 countries, our results showed that ICT infrastructure, human capital and e-participation had a direct relationship with e-government maturity. Of the three dimensions of e-participation, e-information sharing and e-decision-making were positively associated with e-government maturity, and e-consultation was negatively related. Further, all three dimensions of e-participation partially mediated the influence of ICT infrastructure and human capital on e-government maturity. Results also indicated that governance in a country did not significantly contribute to its e-government maturity, and their relationship was not mediated by e-participation. Our findings contribute to the theoretical discourse on e-government by identifying the contextual factors affecting e-government maturity, and provide indications to practice on enhancing government’s willingness in implementing relevant e-participation initiatives.