The study examined determinants of income diversification among arable crop farmers in Osun state, Nigeria. A total of 120 arable crop farmers were proportionately selected from the three agricultural zones in the State that was used for the study. Structured interview schedule was used to elicit relevant information from respondents. Frequencies, percentages, mean and standard deviation, diversity index and Tobit regression model were employed in data analysis. The majority of the farmers had access to farm credit and mean diversity index was 0.46. Factors influencing income diversification among respondents were age (t=-2.68, p≤0.01), credit (t=2.29, p0.05), household size (t=8.24, p≤0.01) and frequency of extension visits (t=2.24, p≤0.05). Only 6.67% of the farmers had income diversity index of 0 meaning that most of the respondents adopted multiple income generating-activities while crop farming remained their dominant income source. In the face of climate change and its attendant risks including total crop failure, farmers should be exposed to other viable farm and off-farm income generating activities, while they are provided with credit facilities to harness such opportunities. Keywords: Income diversification, Arable crop farmers, Income generating activities