Fuel nozzles for gas turbines are provided that include liquid fuel cartridges. In one embodiment, a fuel nozzle includes a fuel plenum plate separating an air plenum from a fuel plenum. The fuel nozzle also includes a plurality of mixing tubes extending through the fuel plenum from the fuel plenum plate to a face plate. Each mixing tube includes an air inlet configured to receive air from the air plenum, a fuel inlet disposed in a tube wall within the fuel plenum to direct fuel from the fuel plenum into the mixing tube to produce a fuel-air mixture, and a fuel-air outlet configured to discharge the fuel-air mixture away from the face plate into a combustion region. The fuel nozzle further includes a liquid fuel cartridge extending through the air plenum and the fuel plenum to the face plate. The liquid fuel cartridge includes a liquid fuel passage.