Smiles, Samuel (1812–1904), biographer, didact and railway administrator, was born on 23 December 1812 in Haddington, East Lothian. His early education took place in Haddington and in 1826 he was apprenticed to a firm of medical practitioners there. From 1829 he studied medicine at Edinburgh University, qualifying in 1832. He returned to Haddington to practice as a surgeon and general practitioner, also giving popular lectures on chemistry, physiology and health. He contributed articles to the Edinburgh Weekly Chronicle, and in 1837 his book, "Physical Education, or, The Nurture and Management of Children", was published.

In 1838 Smiles gave up medical practice and took up the post of editor with the radical journal, the Leeds Times. He was the first secretary of the Leeds Household Suffrage Association which campaigned for the redistribution and extension of the franchise. In 1842 he resigned his position at the Leeds Times to concentrate on delivering lectures and pieces of literary journalism.

In 1845 he was appointed assistant secretary of the newly formed Leeds and Thirsk Railway, which became the Leeds Northern Railway in 1851. In 1849 he wrote an essay entitled Railway Property, its Conditions and Prospects. He was secretary of the board that managed the newly built Leeds Central Station. He played a prominent role in the negotiations to amalgamate the Leeds and Thirsk Railway with the North Eastern Railway, losing his position when the amalgamation took place in November 1854. He then became secretary of the South Eastern Railway, a post he held from November 1854 until 30 August 1866, when he became president of the National Provident Institution.

Smiles wrote many books, including the didactic works "Self-Help" (1859), "Character" (1871), "Thrift" (1875) and "Duty" (1880). He also wrote biographies of industrial figures, including The Life of George Stephenson, which was published in 1857 (he maintained a long-standing association with Stephenson after meeting him at the opening of the North Midland Railway in 1840).

Smiles died in Kensington, London, on 16 April 1904.