Jamie S. Farnes (born 1984) is a British cosmologist, astrophysicist, and radio astronomer based at the University of Oxford. He studies dark energy, dark matter, cosmic magnetic fields, and the large-scale structure of the universe. In 2018, it was announced by Oxford that Farnes may have simultaneously solved both the dark energy and dark matter problems, using a new negative mass dark fluid toy model that "brings balance to the universe". In 2019, the Farnes Universe was listed as one of the top 10 dark matter candidates.