Opportunities for Non-developed Sites to Have Opportunities to be Rehabilitated for Economic Development Act of 2023 or the ONSHORE Act of 2023 This bill establishes the Critical Supply Chain Site Development grant program within the Department of Commerce to develop or expand industrial sites and promote foreign direct investments in industries of strategic importance, particularly in economically disadvantaged areas. Grants may be used for construction of on-site utility infrastructure, investments in site readiness such as zoning and environmental reviews, and job training and retraining programs.