services, market and introducing new technologies are forwarded as recommendations. Ethiopia is one of the most vulnerable countries of the world to the impacts of climate variability and socio economic factors that makes smallholder farmers food insecure. The study was conducted in five kebeles of Assosa district in Benishangul Gumuz Region on the impact of climate variability and socio economic factors on food security of smallholder farmers. The overall objective of the study was to investigate the impact of climate variability and socio economic factors on food security of smallholder farmers. The study was used purposive sampling to select both woreda and kebeles and household heads were selected by systematic random sampling. The size of the sample household respondents were 312 out of which 79 participants were female headed households; one FGD in each kebele with ten members of participants and one key informant interview were held. Both qualitative and quantitative methods of data collection and analysis were used. The study used primary data through interview of households, FGDs and key informant interviews. The study also used secondary data of temperature and rainfall data from 1981 to 2021 years from NMA and NASA gridded data to examine the trend of climate variability. Binary logistic regression was used to see the relationships between dependent and independent variables. The average temperature variability of the woreda shows an increasing trend in the past four decades. Similarly, there is declining trend of rainfall in the past four decades showing high variability. Based on the result of the study the frequency of drought has increased from time to time, flood, diseases of animals, crop failure and soil erosions are the most impact of climate variability in the study area. Less price food, depend on wild food, reduce meal size and additional income are the most coping/ adaptation strategies of smallholder farmers. The binary model results reveals that the respondent’s age, educational status, access to extension and farm experience have a positive and significant effect on food security of smallholder farmers. On the other hand sex of household heads, access to extension services, farm land size, access to market and access to credit have negative and significant effect on food security of smallholder farmers in the study area. Therefore, there are about 76.9 of the respondents are food insecure. Providing training, increasing accessibility to infrastructures, credit