Direct-methanol fuel cells or DMFCs are a subcategory of proton-exchange fuel cells in which methanol is used as the fuel. Their main advantage is the ease of transport of methanol, an energy-dense yet reasonably stable liquid at all environmental conditions.

Whilst the thermodynamic theoretical energy conversion efficiency of a DMFC is 97%; the currently achievable energy conversion efficiency for operational cells attains 30% – 40%. There is intensive research on promising approaches to increase the operational efficiency.

A more efficient version of a direct fuel cell would play a key role in the theoretical use of methanol as a general energy transport medium, in the hypothesized methanol economy.