Sir John Milsom Rees, KCVO (20 April 1866 – 25 April 1952), was a Welsh surgeon and a specialist in laryngology.
He was born at Neath, and studied medicine at St Bartholomew's Hospital in London. After qualifying as an F.R.C.S. at Edinburgh, he obtained a post as surgeon to the Ear, Nose and Throat Department at the Prince of Wales General Hospital in Tottenham. He also practised privately at 18, Upper Wimpole Street, and was employed as a consultant by the Royal Opera House, Covent Garden. The singers he treated included Adelina Patti, Nellie Melba and Kirsten Flagstad. He also treated King George V of the United Kingdom and several other members of the royal family. He was knighted in 1916. He retired to Broadstairs in Kent, where he died.