Background: Availability and quality of nutrition-related health-promoting interventions (N-HPIs) vary across primary schools. We examined whether school contextual factors (e.g., socioeconomic deprivation) were associated with N-HPI availability in Quebec, Canada, and whether available N-HPIs incorporated evidence-based implementation characteristics. Methods: In a cross-sectional study (2016-2019), informants from 171 primary schools reported on N-HPI availability. Availability was analyzed in relation to 10 school-level contextual indicators. A subset of 52 N-HPIs was examined in-depth for alignment with 15 evidence-based implementation characteristics identified in a literature review. Results: N-HPIs were reported in 120 schools (70%, including 77% serving disadvantaged populations). Among the 52 N-HPIs examined in-depth, over 75% demonstrated four core characteristics: Staff involvement, integration of multiple core competencies, innovative teaching strategies, and alignment with school context. Fewer HPIs included formal evaluation (46%), were delivered over multiple sessions (35%), or engaged students in design or implementation (15%). Implications: To strengthen N-HPIs, policymakers should support flexible, theory-informed interventions that incorporate evaluation from the outset. Greater involvement of students, staff, and families in planning may help address persistent barriers. Conclusion: While N-HPIs are widespread and often incorporate evidence-based implementation characteristics, there is room to enhance student participation, extend program duration, and strengthen evaluation.