Climate variability presents important challenges to smallholder crop production, particularly in areas where farming systems depend largely on seasonal rainfall. This study examined farmers’ perceived patterns of climate variability and the adaptation responses adopted by smallholder crop farmers in Imo State, Nigeria. A multistage sampling procedure was used to select 120 food-crop farmers from the state’s three agricultural zones. Primary data were collected through structured questionnaires supplemented with oral interviews. Data were analysed using descriptive statistics, frequency counts, percentages, mean scores, ranking and a Climate Variability Perception Index. Results showed that farmers perceived clear evidence of climate variability, with an overall mean perception score of 3.71. The major perceived indicators were erratic rainfall (mean score: 4.58), increased temperature (4.40), rising incidence of pests and diseases (4.39), unpredictable weather conditions (4.23), occasional flooding (4.08) and shortened rainy seasons (3.71). Farmers disagreed with increased drought occurrence and prolonged drought periods, which recorded mean scores of 1.33 and 2.95, respectively. The main adaptation responses adopted were early planting (37.1%), zero tillage (14.4%), mixed cropping (12.0%), use of hybrid varieties (12.0%), erosion control measures (9.6%) and flood control using channels and gutters (7.2%). The findings indicate that smallholder crop farmers in Imo State recognise changes in climatic conditions and respond mainly through low-cost agronomic practices. The study recommends improved climate information services, stronger extension support and better access to affordable climate-smart agricultural technologies to enhance farmers’ adaptive capacity.