Sir William Allan, DL (1837 – 28 December 1903) was a Liberal Party politician in the United Kingdom. He was Member of Parliament for Gateshead from 1893 until his death in 1903.
Sir William's professional career was as a steamship engineer in the early years of construction of these vessels and his business was the Scotia engineering works in Sunderland, England. He was also involved with a sea line, the Albyn Line, which bore the beginning letters of his surname. His early life included crew experience on steamships which were at one stage gun-running to America during the American Civil War, and he wrote of a number of dangerous escapades during this time.
He was knighted in the 1902 Coronation Honours.
His son, Walter Beattie Allan, published a book which was an illustrated account of his life, for his grandchildren. William Allan published a number of books of traditional Scottish poetry.