Abstract: An interlocking panel truck bed liner comprises a horizontal grid base formed in a solid planar rectangular configuration. The base has an upper surface and a lower surface. The lower surface includes coupling devices to permit affixation to the floor of a truck bed. The upper surface has a plurality of perpendicularly intersecting, rectangular-shaped horizontal grooves. Four vertical sidewall liners are each formed in a solid planar rectangular configuration with a front surface and a rear surface. The rear surface of each sidewall liner includes coupling devices to permit vertical affixation to the sidewalls and tailgate of a truck. The front surface of each sidewall liner includes vertical grooves positioned in alignment with the grooves in the grid base. A plurality of interlocking panels are each formed in a planar rectangular configuration. Each panel has two identical surfaces. The panels are positioned vertically in an operative orientation and include a plurality of coupling devices.