Charles Alston (1683 – 22 November 1760) was a Scottish botanist.
Alston was born in Hamilton, South Lanarkshire, and was apparently raised by the Duke and Duchess of Hamilton.
In 1715 he went to Leyden to study under the Dutch physician Hermann Boerhaave. On his return to Scotland he became lecturer in materia medica and botany at Edinburgh and also superintendent of the botanical gardens. He was a critic of Linnaeus's system of plant classification.
He is buried in Canongate Kirkyard on the Royal Mile in Edinburgh, immediately east of the church.
The tree genus Alstonia is named after him.