Prof Matthew Forster Heddle FRSE (28 April 1828 – 19 November 1897) was Scottish physician and amateur mineralogist active through the 19th century.
He was born at Mellsetter, Hoy in Orkney, the son of Robert Heddle (1780-1842) and his wife, Henrietta Moodie.
After receiving his early education at Edinburgh Academy 1837 to 1843 he moved to Merchiston Castle School. In 1845 he entered as a medical student at the University of Edinburgh, and subsequently studied chemistry and mineralogy at Klausthal and Freiburg. In 1851 he took his degree of MD at Edinburgh, and for about five years practised there.
In the 1850s, together with Patrick Dudgeon, he undertook a survey of the Faroe Islands also collecting many minerals. This was followed by similar survey expeditions to the Shetland Islands and Orkney. They co-founded the Mineralogical Society of Great Britain in 1876.
Medical work, however, possessed for him little attraction. He became an assistant to Prof. Connell, who held the chair of chemistry at St Andrews, and in 1862 succeeded him as professor. This post he held until in 1880 he was invited to report on some gold mines in South Africa. On his return he devoted himself with great assiduity to mineralogy, and formed one of the finest collections by means of personal exploration in almost every part of Scotland. His specimens are now in the Royal Scottish Museum at Edinburgh. In 1874 he joined Ben Peach on various scientific explorations and from 1878 was also joined by John Horne.