This master’s thesis studies four Faith-Based Humanitarian Organizations (FBO) in the international humanitarian sector: World Vision International (WVI), Catholic Relief Services (CRS), Islamic Relief Worldwide (IRW) and Tzu Chi Foundation (TCF). Using a theoretical framework based on organizational identity, the research examines from the FBOs own views the causes behind their origins, the impact of external factors on their identities and strategies, their current self-perception, and provides insights for future faith-based humanitarian work. Through the qualitative methods, digital archival design and online semi-structured interviews with senior staff, the study’s findings shows that each FBO was started as a response to a specific humanitarian tragedy and was driven by religious motivation. Since the origin, the FBOs have adapted their organizational identities and operational strategies to external factors. WVI and CRS have gone from church-based to community-based approaches, IRW has worked to demystify Islam in humanitarian work, and TCF maintained a consistent Buddhist-based approach through for example a TV channel and academic symposiums. The research identifies the crucial need for FBOs to balance their religious identities with secular humanitarian principles, focusing on localization, community engagement, interfaith cooperation, and strategic presentation of religious identities. To build on this thesis, future research can focus on investigating and comparing more FBOs, their roles in disaster preparedness and communication strategies.