State governments are regularly reexamining the statewide board governance arrangements over public higher education, enacting governance reforms that change the structure or authority granted to boards by state legislatures. While previous research has studied governance reforms, there is a lack of recent studies on such reforms and what governance reforms look like for different sectors within public higher education. This dissertation examines the political, socioeconomic, and organizational factors associated with state-level postsecondary governance reform adoption over the last two decades, from 2000 to 2020. I apply a revised policy innovation and diffusion theoretical framework to examine the state-level factors that are associated with any type of governance reform, governance reform by sector, the type of governance reform by sector (e.g., changes in the structure of a board or changes in the authority granted to the board), and governance reforms that enhanced state authority. I drew on a unique longitudinal dataset that combines information on state higher education governance reform by sector gathered from state legislation and publicly available data on features of states and institutions and used panel analysis with fixed effects to answer my research questions. Though my results were mixed, over all this study shows that political and socioeconomic factors are most closely related to governance reform adoption. I close by providing insight into these results and their theoretical contributions and offer directions for future research. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]