Algae fuel, algal biofuel, or algal oil is an alternative to liquid fossil fuels that uses algae as its source of energy-rich oils. Also, algae fuels are an alternative to commonly known biofuel sources, such as corn and sugarcane. When made from seaweed (macroalgae) it can be known as seaweed fuel or seaweed oil.
In December 2022, ExxonMobil, the last large oil company to invest in algae biofuels, ended its research funding.
Algal fuels boast high yields, a high ignition point, and can be cultivated with minimal impact on freshwater resources.