<strong>Background:</strong> Campus shootings, though infrequent, result in significant loss of life, psychological trauma, and disruption to university communities. Traditional preparedness programs developed for K-12 settings do not translate well to university environments. Virtual reality (VR) offers an immersive and engaging method to enhance situational awareness and decision-making during high-stress events. <strong>Objective:</strong> This study aimed to develop the Safe@Campus prototype, a theory-informed, stakeholder-engaged VR-based prototype designed to prepare university students to recognize and respond to campus shooting threats, and to evaluate its initial usability and feasibility among undergraduate students. <strong>Methods:</strong> We followed a 2-phase, user-centered design process. Phase I (stakeholder-informed feasibility assessment and prototype refinement): through interviews with campus safety experts, firearm safety practitioners, school safety specialists, and students, we identified key content, scenario requirements, and implementation considerations. A 360-degree video–based VR prototype depicting an active shooter incident in a university classroom was developed using Unity3D, incorporating branching decision points aligned with the “run, hide, or fight” framework. Expert and user feedback guided iterative refinements. Phase II (student usability and acceptability testing): 2 focus groups with undergraduates at The Ohio State University (N=17) viewed a VR scenario and then participated in guided discussions about prior training experiences, the acceptability of VR, and recommendations for improvement. Transcripts were analyzed using constant comparative methods in ATLAS.ti (version 25). <strong>Results:</strong> The first focus group comprised 8 students (n=5, 63% female; n=3, 38% White, n=4, 50% Asian/Asian American), and the second comprised 9 students (n=6, 67% female; n=6, 67% White). Across both groups, 82% (14/17) reported participating in active shooter drills during K-12 schooling, yet many felt these experiences did not adequately prepare them for the complexity of university environments. The following four major themes emerged: (1) prior experience with active shooter drills: K-12 drills varied widely in realism and left students uncertain about appropriate actions in university settings; (2) need for university-specific training: participants noted substantial gaps in preparedness and expressed strong support for required, standardized training; (3) perceived usefulness of VR: students found VR highly engaging, realistic, and effective for reinforcing situational awareness and decision-making; and (4) recommendations for prototype improvement: students suggested increasing interactivity, adding time-pressured decisions, expanding scenarios to diverse campus spaces, and integrating the program into required university activities such as orientation. <strong>Conclusions:</strong> Safe@Campus is a feasible, acceptable, and engaging VR-based approach to campus shooting preparedness. Students viewed the immersive, decision-driven format as an effective way to build practical skills not addressed by traditional training. Future development should expand scenario diversity, increase interactivity, and evaluate program effectiveness in larger trials. <strong>Trial Registration:</strong>
