The scientist credited with the discovery of the electron is J.J. Thomson. In 1897, through his experiments with cathode rays, Thomson demonstrated the existence of negatively charged particles, fundamentally changing the understanding of atomic structure. This groundbreaking work led to the development of the plum pudding model of the atom and paved the way for future research in quantum physics. His discoveries earned him the Nobel Prize in Physics in 1906, marking him as a pivotal figure in the history of modern science.