Fiber-reinforced grid stiffened panels have found application in civil and military aviation and are recognized as being damage tolerant due to the unidirectional nature of the stiffener ribs being less prone to delamination between plies. Conventional manufacture of composite grid stiffeners requires the use of complex tooling which has severely limited the use of these structures. This effort investigates the mechanical properties of a grid stiffened panel produced using a continuous fiber direct digital manufacturing process, where the skin and ribs are additively manufactured, with the goal of removing the need for complex tooling. Commingled E-glass/PET tow, having a fiber volume fraction of 53%, is used in this work, as the high fiber content mimics the composites of grid stiffeners produced using conventional manufacturing approaches. The rib stiffeners on the grid stiffened panel are manufactured using a continuous deposition path, taking advantage of tow steering to create the more complex grid architecture. Programmed, variable levels of in situ consolidation force are employed to enable equal heights of the stiffener and grid nodes. The results of the mechanical testing performed indicate the effectiveness of the direct digital manufacturing approach and the overload failure load bearing capacity of the fiber-reinforced thermoplastic composite structure. Thus, direct digital manufacture of continuous fiber-reinforced thermoplastic matrix composite grid stiffened panels is shown to remove the need for complex, dedicated tooling, while providing mechanical performance that’s not too far off what would be expected from a more traditionally manufactured composite grid stiffened panel.