Background: Ending food insecurity is one of the goals of Sustainable Development Goals (SDGs). It is also one of the serious problems of Ethiopia. However, there is a dearth of studies that show the status of food insecurity among lactating mother in Ethiopia including the study area. Therefore, the objective of this study is to assess the predictors of food insecurity among lactating mothers in Ataye District, North Shoa, and Central Ethiopia. Methods: A community-based cross-sectional study design was used among 612 lactating mothers aged 15-49 years. The food insecurity was determined by computing nine standards Household Food Insecurity Access Scale (HFIAS) questions. A structured interviewer-administered questionnaire was used to collect the data. Data were entered into EpiData version 4.2 and exported to SPSS (Statistical Package for Social Science) version 24 for analysis. Odds ratio with 95% confidence interval was used for the predictors of food insecurity using bivariate and multivariate logistic regression analysis. Results: The prevalence of food insecurity among lactating mothers was 36.8%. No formal education [(AOR=1.82, 95% CL: (1.13, 2.92)], no income-generating activities [(AOR=3.39, 95% CI: ((2.05, 5.64))], no home gardening practices [(AOR=5.65, 95% CI: (3.51, 9.08)], alcohol use by husbands [(AOR=2.02, 95% CI: (1.25, 3.24)], low minimum dietary diversity scores [(AOR=2.94, 95% CI: (1.88, 4.57)], less than three frequencies of meals [(AOR=3.97, 95% CI: (1.65, 9.54)] and three meals only per day [(AOR= 1.86, 95% CI: (1.08, 3.17)] were significant predictors of food insecurity of mothers. Conclusion: The prevalence of food insecurity was high in the study area. No formal education, no income-generating activities, no home gardening practice, alcohol use by husbands, low minimum dietary diversity score, fewer than three frequencies of meals and three meals only per day were independent predictors of food insecurity. Therefore, increasing home gardening, decreasing alcohol intake, increasing dietary diversity, and performing income-generating activities are highly recommended to reduce food insecurity.