Roger Llewelyn Davies (born 13 January 1954) is a British astronomer and cosmologist, one of the so-called Seven Samurai collaboration who discovered an apparent concentration of mass in the Universe called the Great Attractor. He is the Philip Wetton Professor of Astrophysics at Oxford University. His research interests centre on cosmology and how galaxies form and evolve. He has a longstanding interest in astronomical instruments and telescopes and developed the scientific case for the UK's involvement in the 8m Gemini telescopes project. He has pioneered the use of a new class of astronomical spectrograph to measure the masses and ages of galaxies, as well as search for black holes in their nuclei. He is the founding Director of the Oxford Centre for Astrophysical Surveys which is funde