Abstract: Women play a critical role in agricultural activities, yet their contributions to household food security are often undervalued and under-supported. Despite their central involvement in food production, women are frequently excluded from key decision-making processes related to agriculture and food security. This study investigated the effect of women’s participation in agriculture on sustainable household food security in Baringo County. The research aimed to explore how women’s involvement in agricultural activities impacts food security outcomes at the household level. The study adopted a cross-sectional research design with a mixed methods approach, utilizing both qualitative and quantitative data. A sample of 316 registered members of SMART Agriculture and 6 field officers were selected through random and purposive sampling. Data was collected using structured questionnaires and interviews. The findings revealed that a majority of respondents felt women were not sufficiently involved in decision-making regarding household food security, and there was a noticeable gender disparity in contributions to food production. Despite this, many respondents acknowledged the growing role of women in agricultural activities and their positive impact on household food security. The study’s results indicate a strong positive correlation between women’s participation in agriculture and sustainable food security, as demonstrated by a Pearson correlation coefficient of 0.684 (p = 0.000). The study concludes that increasing women’s involvement in agriculture significantly enhances food security outcomes, emphasizing the need for policies that promote gender inclusion in agricultural decision-making and community support for women.