Dolly (5 July 1996 14 February 2003) was a female Finnish Dorset sheep and the first mammal cloned from an adult somatic cell. She was cloned by associates of the Roslin Institute in Scotland, using the process of nuclear transfer from a cell taken from a mammary gland. Her cloning proved that a cloned organism could be produced from a mature cell from a specific body part. Contrary to popular belief, she was not the first animal to be cloned.The employment of adult somatic cells in lieu of embryonic stem cells for cloning emerged from the foundational work of John Gurdon, who cloned African clawed frogs in 1958 with this approach. The successful cloning of Dolly led to widespread advancements within stem cell research, including the discovery of induced pluripotent stem cells.Dolly lived at the Roslin Institute throughout her life and produced several lambs. She was euthanized at the age of six years due to a progressive lung disease. No cause which linked the disease to her cloning was found.Dolly's body was preserved and donated by the Roslin Institute in Scotland to the National Museum of Scotland, where it has been regularly exhibited since 2003.

Roslin (formerly spelt Rosslyn or Roslyn; Scottish Gaelic: Riasg Linne) is a village in Midlothian, Scotland, 11 kilometres (7 mi) to the south of the capital city Edinburgh. It stands on high ground, near the northwest bank of the river North Esk.