Disclosed are a separator for a fuel cell that improves power characteristics of the fuel cell, and a fuel cell including the same. The separator includes a plurality of current-carrying units, and an insulating unit interposed between the current-carrying units, wherein each current-carrying unit includes a first polymer matrix in which carbon-based particles are dispersed, and the insulating unit includes a second polymer matrix in which insulating inorganic particles are dispersed. The separator for fuel cells includes an insulating unit that exhibits low gas permeability and superior electrical insulation property, and the current-carrying unit that exhibits superior strength characteristics and conductivity, thus increasing voltage generated per one cell and considerably increasing a power generated per a constant area, when applied to the fuel cells.