Over the last decade, new technologies and data sources have enabled the emergence of "digital humanitarianism". Digital humanitarianism is exemplified by web mapping initiatives such as the Humanitarian OpenStreetMap Team and Ushahidi, in which large numbers of geographically-disparate lay volunteers collaboratively produce, process, and map humanitarian data. The Humanitarian OpenStreetMap Team, for example, is an online community that collaboratively maps humanitarian crisis zones; Ushahidi is a website that collects and maps social media and SMS messages in similar contexts. While digital humanitarianism shifts the technologies and sources of data that can be engaged to respond to humanitarian crises and emergencies, it has emerged alongside hyperbolic claims of its "revolutionary" potential and "egalitarian" nature. Most digital humanitarian research remains descriptive and focuses on its constituent technologies, data, and new operational capacities. This dissertation explores digital humanitarianism as a set of socio-technical practices and political-economic relations, showing its uneven impacts, contingent nature, and attendant struggles around knowledge incorporation and representation. It offers a critical interrogation of the deliberations and relations that influence how formal humanitarian agencies use spatial technologies and data to frame and address problems. I theorize the ways digital humanitarianism emerges from - and in turn impacts - neoliberal reforms of the formal humanitarian and emergency management sectors. I begin by constructing a theorization of digital humanitarianism that departs from current understandings, by foregrounding its practices, politics, and transformations. I then argue that digital humanitarianism alters how data are collected and produced, primarily focusing on crowdsourcing and social media. These new sources of data do not immediately align with existing formal-sector workflows, so in order to "tame" these data digital humanitarians negotiate new forms of data abstraction, categorization, and generalization. Next, I theorize the ways digital humanitarians produce those in need of their technologies and labor. In these efforts they usually develop new technologies first, subsequently articulating the formal sector's need for that technology. I then explain that digital humanitarianism both results from and reinforces neoliberal reforms, fostering new forms of capital accumulation through "philanthro-capitalism". This research contributes to geographic research by illuminating the representational and socio-technical processes and practices that constitute new spatial technologies, and by elucidating the perpetuation of humanitarian imaginaries in digital technologies.