Electrons and photons are neither particles nor waves. They are quantum-mechanical entities which exhibit properties that we may sometimes ascribe to classical particles, and sometimes to classical waves. But they are not classical particles, and they are not classical waves; and, most importantly, they are not sometimes classical particles and sometimes classical waves. They are quantum-mechanical objects all the time.
This being said, all aspects of reality are, as far as we know, accurately described by the laws of quantum mechanics, and therefore, all objects are quantum, so to speak. In this sense, we could say, as rob mentions in the comments, that all particles are waves (with the qualification from the previous paragraph).