After returning to Australia, Ryrie remained the Member for North Sydney. In 1920, he was made an Assistant Minister for Defence in the ministry of Billy Hughes, assisting Senator George Pearce. At the 1922 election the newly created Division of Warringah was carved out of part of North Sydney, and Ryrie transferred there to be succeeded by Hughes. He served until 1927, when he was appointed the Australian High Commissioner to the United Kingdom in London. He was also an Australian delegate to the League of Nations. In 1928 and 1929 Ryrie acted as the Australian accredited representative before the League's Permanent Mandates Commission for the annual examinations of the Australian administration of the Mandated Territory of New Guinea.