Agriculture remains a critical driver of economic development, employment creation, poverty reduction, and food security in Nigeria. However, the achievement of sustainable agricultural development depends significantly on the active participation of key productive groups, particularly women and youth, as well as access to adequate agricultural finance and institutional support. This study evaluated the effect of women and youth participation on agricultural development, with particular emphasis on sustainable agriculture and food security in Nigeria. Anchored on Sustainable Agricultural Theory, the study examined how factors such as access to agricultural credit, leadership and institutional support, ecological challenges, and the attitudes and participation of women and youth influence agricultural development and food security outcomes. An ex post facto research design was adopted for the study. The study population comprised 160 respondents, including women, youth, farmers, and civil servants drawn from three selected states in Nigeria. Using convenience sampling, a sample of 150 respondents was selected. Data were collected through a researcher-developed 25-item structured questionnaire based on a five-point rating scale and analysed using descriptive statistics, including percentages, mean scores, standard deviations, and relevant inferential statistics for hypothesis testing at the 0.05 level of significance. The findings revealed that women and youth participation, access to agricultural credit, leadership and institutional factors, and ecological conditions significantly influence agricultural development and food security. The study further established that inadequate financial support, weak institutional coordination, unfavourable environmental conditions, and limited participation of women and youth constitute major constraints to sustainable agricultural development. The study concludes that strengthening the productive and entrepreneurial participation of women and youth, alongside improved access to agricultural financing, institutional support, and effective monitoring mechanisms, is essential for advancing sustainable agriculture and ensuring long-term food security in Nigeria. It is therefore recommended that government and relevant stakeholders establish effective monitoring and feedback mechanisms, expand inclusive agricultural financing, and implement targeted capacity-building and empowerment programmes for women and youth in the agricultural sector.