Sir William Shelford KCMG (1834–1905) was an English civil engineer.
Born at Lavenham, Suffolk on 11 April 1834, he was eldest son of Rev William Heard Shelford (1799–1856), Fellow of Emmanuel College, Cambridge, and rector of Preston St. Mary, Suffolk; his mother was Emily Frost née Snape (1809–1889), eldest daughter of Rev. Richard Snape, rector of Brent Eleigh. Among his brothers, Thomas Shelford (1839–1900) became a member of the legislative council of the Straits Settlements, and was made C.M.G., while Rev. Leonard Edmund (1836–1914) was a clergyman. In February 1850 Shelford went to Marlborough College, leaving at midsummer 1852 to become an engineer. He was first apprenticed to a mechanical engineer in Scotland, but in 1854 he became a pupil of William Gale, a waterworks engineer of Glasgow. During his two years' term of service he attended lectures at Glasgow University.
In 1856, thrown on his own resources after his father's death, Shelford left Glasgow for London, and in December of that year he entered the office of John Fowler as an assistant engineer, remaining there until 1860. He was engaged on the Nene River navigation and improvement works, of which he was in time placed in charge, until 1859, when he was transferred to London and was engaged on the laying-out and construction of the first section of the Metropolitan Railway. Leaving Fowler's service in the autumn of 1860, Shelford became an assistant to F. T. Turner, joint engineer with Joseph Cubitt on the London, Chatham and Dover Railway.
After employment on surveys Shelford was appointed resident engineer on the high-level railway to the Crystal Palace, the Act of Parliament for which was passed in 1862. Apart from decorative work on the stations, he designed and superintended all the engineering works on that line. In 1862–5 he was also engaged, under Turner, as resident engineer on the eastern section of the London, Chatham and Dover Railway, to Blackheath Hill.