Röntgen or Roentgen may refer to:
- Roentgen (unit), unit of measurement for ionizing radiation, named after Wilhelm Röntgen
- Wilhelm Röntgen (1845–1923), German physicist, discoverer of X-rays
- Abraham Roentgen (1711–1793), German cabinetmaker
- David Roentgen (1743–1807), German cabinetmaker, son of Abraham Roentgen
- Heinrich Röntgen (1787–1813), German explorer
- Julius Röntgen (1855–1932), German-Dutch composer of classical music
- Kevin Roentgen, musician, singer with American rock band Orson
- Roentgen (album), by Japanese singer Hyde