Abstract: A quick-release clamp is provided having a retaining bracket fixed to the vehicle, a clamping arm for releasably engaging a portion of the seat leg, and an interlocking mechanism detachably secured to the retaining bracket for fixedly mounting the clamping arm and the seat engaged thereby. The retaining bracket includes a keyed slot leading to an enlarged cavity. The clamping arm includes a hooked portion for overlaying the seat leg. The interlocking device includes a bolt having a T-shaped or winged head which is insertable within the keyed slot and rotatable within the cavity to a position which prevents its removal through the keyed slot. One end of the bolt passes through the clamping arm and a locking handle is secured to that end. Upon initial locking rotation of the locking handle, the bolt head rotates within the cavity to the non-removable position.