Abstract Sri Lanka's agricultural sector has an abundant supply of natural resources that can be further developed and utilized to produce bio-fuels. Transformation of the nation's significant renewable biomass resources into cost-competitive, high-performance bio-fuels could reduce the country's dependence on imported fossil fuels and enhance energy security. However, there is limited understanding of the potential of bio-fuel resources, their utilization, and economic potential. This study evaluates the economic competitiveness of producing ethanol from sugar, starch and cellulosic feedstock. The net economic returns model was used to select economically feasible feedstock for bio-fuel production. For each feedstock, net present value, feedstock cost per British thermal unit (Btu) and per gallon of ethanol, and break-even price of feedstock and ethanol were calculated. Cellulosic feedstock showed the lowest feedstock cost per gallon of ethanol. Sugarcane, cassava, corn, and cellulosic feedstock appeared to be the leading bio-fuel crops among the investigated crops. For cellulosic feedstock, however, the process of converting the feedstock into ethanol is still in the demonstration phase; hence, results should be interpreted with caution.