Herder counter-productive activities-induced food insecurity is a threat to achieving the number 2 SDGs (zero hunger) in Nigeria. Although studies have been conducted to address the herder-farmer conflict challenge, however, the studies focused majorly on North central Nigeria while not many studies have been done in Southwestern Nigeria. Thus, this study examines herder counter-productive-induced food insecurity in Ekiti and Ondo states, Nigeria to add to the existing knowledge on this challenge. A multistage sampling procedure was used to select respondents for the study. Primary data were collected from 380 farmers in the study area. Descriptive statistics and a probit regression model were used to analyze the socio-economic characteristics of the respondents and the effects of the Fulani herdsmen's counter-productive activities on farmers’ food security status respectively. The result showed that herder counter-productive activities have a positive and significant influence on the farmers’ food insecurity. The results also showed that while factors such as off-farm income, safety net programme, private transfer, farmers’ group membership, and asset ownership reduce food insecurity, household size and Fulani herdsmen attacks increase food insecurity. The government should do more in terms of providing a safety net for victims of herdsmen attacks while farmers should diversify their livelihood activities as well as join groups to access the benefits inherent in groups. Keeping cattle in ranches by the herders also has the potential to resolve the challenge in Nigeria.