Donkin is an underground coking and thermal coal mine on Cape Breton Island, Nova Scotia, Canada. The project was won in a government tender by Xstrata and a predecessor, Morien Resources, in 2005 but is now a wholly-owned subsidiary of the Cline Group, Kameron Collieries ULC. The room and pillar mine operate under the Atlantic Ocean. Domestic coal is sold to Nova Scotia Power, and export coal is shipped through the Atlantic Canada Bulk Terminal. The mine reopened in late 2022 after closure in March 2020 due to challenging roof control conditions coupled with a decline in export prices. Since July 2023, the mine has been idle due to roof stability problems.