Colonel Sir John Wallace Pringle, CB, FRGS (23 May 1863 - 16 July 1938) was a British engineer who was Chief Inspecting Officer of the Railways Inspectorate of the Ministry of Transport from 1916 to 1929. As such he was in charge of investigations into a number of serious railway accidents in the UK.
Pringle became a lieutenant in the Royal Engineers in 1883. As an army officer, Pringle fought in the Third Anglo-Burmese War, 1885-1886. In the Uganda railway survey between 1891 and 1892, Pringle was second in command to James Macdonald. The survey's findings confirmed that the caravan route to the Great Rift Valley was the best path for the line, followed by the easiest gradient to be found over the Mau Escarpment and down to Lake Victoria. Macdonald and Pringle recommended construction of a three-foot six inch gauge railway. They suggested that Kikuyuland would be a suitable place for whites to live, and their civilizing effect would drive out slavery, but the railway was needed to give access to the new colony. Pringle became a Fellow of the Royal Geographical Society. He received the Gill Memorial from this society in 1895 for his work on the Uganda railway survey. In 1896 he was appointed superintending engineer on the survey and construction of the Hyderabad-Godavari Valley Railway.
Pringle had reached the rank of Major in 1900 when he was appointed an inspecting officer in the Board of Trade. At the start of World War I in 1914, he was appointed a deputy director of railway transport with the temporary rank of Colonel. In 1916 he was confirmed in this rank when he returned to the Board of Trade as Chief Inspecting Officer. When the Ministry of Transport was formed in 1919, he was transferred to the new ministry with his department, retaining his position as Chief Inspecting Officer until his retirement in 1929.
Pringle conducted various accident inquiries, including that into the Sevenoaks derailment of 24 August 1927. He chaired a committee to investigate the general adoption of automatic train control on British railways, following the adoption of an electro-mechanical system on the Great Western Railway (GWR), reporting in April 1922. He chaired a second committee on the same subject that reported in 1930, but little was done outside the GWR. He was Chairman of the Electrification of Railways Advisory Committee, which reported in 1928.