Janssen may refer to: Astronomy Janssen (lunar crater) Janssen (Martian crater) Janssen (planet), an exoplanet also known as 55 Cancri e Other Janssen (surname) is a common Dutch surname, cognate of "Johnson" Janssen Biotech, American biotechnology company Janssen COVID-19 vaccine, a COVID-19 vaccine Janssen Pharmaceuticals, a Belgian company , World War II US Navy destroyer escort E. Janssen Building, a historic building in Eureka, California See also Jansen (disambiguation) Janssens