Abstract: A universal clamp is provided for mounting fishing rod holders on rigid surfaces. The universal clamp comprises a main body having three sidewalls. One sidewall has an aperture over which a grooved nut is attached to the sidewall. A bolt is inserted into the nut, the bolt including a metallic disk on one end. A pipe is attached to at least one other sidewall of the main body. The pipe includes a generally centered aperture over which a nut is secured to the pipe, and a hollow cavity for accommodating a stake of a fishing rod holder. A bolt goes through the nut and aperture in the pipe to secure the fishing rod holder stake to the universal clamp. The universal clamp of the present invention allows the use of a fishing rod holder not only on the shores of water basins, but also from boats, bridges, and piers.