This work is about the production of biodiesel from watermelon (Citrullus lanatus) seed oil. The oil extraction was done using solvent extraction method. The basic test for suitability of the obtained watermelon oil was carried out. Using trans-esterification process, watermelon oil was heated to 60˚C, solutions of methoxide (NaOCH3) were also added and stirred continuously for an hour. It was left to settle for 24 hours. After shaking, the mixture was poured into a separating funnel and was allowed to stand for 24 hours. The biodiesel was obtained using the separating funnel, separating biodiesel and glycerine. The washed biodiesel was collected into a beaker and gently heated in an oven at 105˚C to evaporate the excess water and methanol in the biodiesel. The results of the test classified the watermelon biodiesel within limits set for biodiesel’s properties by ISO 14214 specifications on Biodiesel.