The present study investigates the use of modified red mud as a solid base catalyst for biodiesel production. Red mud, a waste from the Bayer process, was treated using soda-lime calcination at various temperatures. The modified red mud was characterized using TG-DTA, XRD, SEM, BET and the Hammett indicator method. The catalytic activity was investigated for the transesterification of canola oil with methanol to biodiesel with a yield of more than 99% under the following conditions: 12:1 methanol/oil molar ratio, 4wt% catalyst concentration, 60 degrees C reaction temperature, and 2 h reaction time. Furthermore, the catalyst can be reused for up to three cycles without any significant loss of activity.