Robert George Spencer Hudson (17 November 1895 – 29 December 1965) was an English geologist and paleontologist.
He was born in Rugby, Warwickshire, the eldest son of Robert Spencer Hudson.
In World War I, he served in the Artists' Rifles and the Royal Warwickshire Regiment, becoming a second lieutenant (acting captain).
He retired from Iraq Petroleum Company in 1958, and became an Iveagh Research Fellow at Trinity College, Dublin in 1960.
In 1958 he was awarded the Murchison Medal by the Geological Society of London for "his significant contribution to the science by means of a substantial body of research."