Johannes Fibiger, Danish physician and academic, Nobel Prize laureate (born 1867)

Johannes Andreas Grib Fibiger was a Danish physician and professor of anatomical pathology at the University of Copenhagen. He was the recipient of the 1926 Nobel Prize in Physiology or Medicine "for his discovery of the Spiroptera carcinoma". He claimed to have shown that the roundworm which he called Spiroptera carcinoma could cause stomach cancer in rats and mice. His experimental results were later proven to be a case of mistaken conclusion.

The Nobel Prize in Physiology or Medicine is awarded yearly by the Nobel Assembly at the Karolinska Institute for outstanding discoveries in physiology or medicine. The Nobel Prize is not a single prize, but five separate prizes that, according to Alfred Nobel's 1895 will, are awarded "to those who, during the preceding year, have conferred the greatest benefit to humankind". Nobel Prizes are awarded in the fields of Physics, Medicine or Physiology, Chemistry, Literature, and Peace.