Food insecurity (FI) has short- and long-term effects on maternal and child health, with persistent inequities within under-resourced communities of colour (e.g., Hispanic and Non-Hispanic Black). Interventions to mitigate maternal-child FI must engage the voices of under-resourced communities of colour to improve implementation and tackle socio-ecological drivers of inequities, leading to positive maternal-child outcomes. This exploratory sequential mixed-methods study aimed to co-create implementation strategies to tailor a culturally sensitive intervention to address FI during the first 1000 days of life in under-resourced communities of colour in Las Vegas. A Community Advisory Board (CAB) engaged in a two-step participatory process. First, through the concept mapping, hierarchical cluster analysis organized 125 strategies into seven thematic areas: policy and advocacy, access to food and resources, built environment, education across systems, social and peer support, cultural congruency and trust, and wellness and mental health. Second, through consensus-building, strategies were combined by similarity (n = 94) and excluded if unrelated to health and nutrition (n = 9). The CAB reached a consensus on 22 strategies classified across three socio-ecological levels. Examples of strategies at the community level (n = 16) included increasing utilization of federal nutrition assistance programmes; at the service level (n = 4), integrating FI screenings and referral coordination systems across services; and at the individual level (n = 2), providing mentorship, education, and support for families and moms. The co-creation of a culturally sensitive intervention to reduce inequities in maternal-child FI during the first 1000 days of life requires multi-level strategies across three socio-ecological levels in under-resourced communities of colour in Las Vegas.