The study assessed the leadership effectiveness among the executives and members of farmers’ cooperative societies in Osun State, Nigeria. A structured interview schedule was used to gather quantitative data from 50 executives and 75 members of farmers’ cooperative societies across the state. Data were processed through IBM SPSS version 23. Descriptive and inferential statistics were used to analyse the data. The findings revealed that the majority (84%, 78.7%) of leaders and members were male and members were male while (98%, 94.5 %) were married with a mean age of 47.46 ± 13.73 and 40.36 ± 10.13 years. Also, the majority of the cooperative leaders emerged through election and mostly selected into leadership position based on active participation in cooperative activites. The majority of the leaders were very effective in leading discussions during meetings (mean=2.90) and managing cooperatives operations (mean=2.63). Also, irregular payment of loans and inadequate trainings were the problems facing leadership effectiveness. Years of farming experience (r= 0.788) and years of cooperative membership (r= 0.731) were significantly related to leadership effectiveness. It is concluded that, in order to enhance leaders’ effectiveness and consequently, agricultural development, capacity building through regular training, and workshops should be organised by relevant stakeholders.