Ronald David Ekers AO (born 18 September 1941) FRS FAA[1] is an Australian radio astronomer.

His fields of specialty include the study of active galactic nuclei, cosmology, and radio astronomy techniques.

After graduating from ANU, his first postdoctoral studies were performed at Caltech, during which time Richard P. Feynman and Fred Hoyle were active.

He is a past president of the International Astronomical Union (IAU) (2003–2006) and a member of the advisory board for the Peter Gruber Foundation Cosmology Prize.

He was elected a Fellow of the Australian Academy of Science, a Foreign Member of the Royal Netherlands Academy of Arts and Sciences in 1993,[2] a Foreign Member of the American Philosophical Society in 2003,[3] a Fellow of the Royal Society in 2005, and a Foreign Associate of the US National Academy of Sciences in 2018.