Hugh Francis Clarke Cleghorn of Stravithie, FRSE FLS LLD (9 August 1820 – 16 May 1895) was a Madras-born Scottish physician who worked in India and pioneered as a botanist and in forest conservancy. Cleghorn, sometimes known as the father of scientific forestry in India, was instrumental in the creation of the forest department in the Presidency of Madras. The plant genus Cleghornia was named after him by the botanist Robert Wight. Cleghorn returned to Scotland in 1869 and developed forestry education in Scotland and established a lecturership at the Edinburgh University.
Cleghorn was born in Madras on 9 August 1820, where his father, Peter (sometime referred to as Patrick) Cleghorn (1 December 1783 – 9 June 1863) was Registrar and Prothonotary (later Administrator-General) in the Supreme Court of the Madras Presidency. His mother Isabella Allan died in Madras (1 June 1824) when he was four years old. His grandfather Professor Hugh Cleghorn (1752–1837) was the first British colonial secretary to Ceylon. The family returned to Stravithie in 1824 and Cleghorn received his early education the High School in Edinburgh. Cleghorn then joined the newly founded Madras College at St Andrews followed by three years at the United College of St Salvator and St Leonard. He also experienced rural life and received a training in agriculture. He then went to study at the University of St Andrews. Graduating in 1837, he went on to study medicine at Edinburgh and for five years he apprenticed under the famous surgeon, James Syme. He qualified MD from the University of Edinburgh in 1841. This was also a period in which he developed an interest in botany. He then qualified for the Indian Medical Service and was posted to the Madras Presidency.
Cleghorn first served in India as an assistant surgeon employed by the East India Company at the Madras General Hospital, then Mysore Commission, until 1848. While at Mysore he took a keen interest in botany, encouraged by Sir William Jackson Hooker who had suggested to him that he "study one plant a day for a quarter of an hour". It was here that Cleghorn began to commission botanical drawings. He also received a list of enquiries to pursue from Robert Christison. He had a lot of time between duty at a jail and a hospital and between postings from Dharwad to Trichinopoly. Cleghorn took a special interest in economic botany became involved with forest conservation in Mysore. In 1848, he suffered from "Mysore fever" and returned to Britain and spent time at Torquay but continued his private studies on botany. He was on the verge of resigning from service when he was requested by John Forbes Royle to assist in the cataloguing of exhibits for the Great Exhibition of 1851. Cleghorn returned to India in 1852 on being appointed Professor of Botany and Materia Medica at Madras Medical College by Sir Henry Pottinger. During this period he also became an active member of the Madras Literary Society and the Madras Agri-Horticultural Society.