Of Toronto, was born at Warwickmains, Ayrshire, Scotland, on the 6th November, 1835. He is the second son of the late Alexander Ralston Langmuir, who married Miss Jane Woodburn, of Aird. John Woodburn Langmuir was an energetic man. Idealist and humanitarian, he set aside his successful business as a shipbuilder and grain merchant in Picton to take on the job of Inspector of Ontario Asylums, Prisons, and Charitable Institutions in 1869. As Inspector, Mr. Langmuir was responsible for provincial institutions for the mentally ill and handicapped, as well as supervising the county jails and other non-federal prisons. No less than eight important public institutions were founded and organized under his supervision and direction during his term of office, viz: The Asylums for the Insane at London and Hamilton; the Asylum for Idiots at Orillia; the Institution for the Deaf and Dumb at Belleville; the Central Prison; and the Mercer Reformatory and Refuge at Toronto.
In 1882, Mr. Langmuir resigned his government office, and associated himself with a number of prominent and wealthy men, in the establishment of the Toronto General Trust Company. The position of general manager of this company he now holds. He is also a director of the Federal Bank of Canada, and is one of the Niagara Falls Park commissioners.
He was major of the 16th Battalion, and served during the Fenian raids of 1866. In politics, he is a Liberal, believing that the principals adopted by the reform party must in the end prevail and prove the best for the country's welfare. He has travelled over the greater part of the American continent. In religion, he is a Presbyterian, as have been his ancestors for many generations.