Hugh Johnston (January 4, 1756 – November 29, 1829) was a Scottish-born merchant and politician in New Brunswick.
He was born in Morayshire, the son of William Johnston and Isabel Hepburn.
Johnston traded fish and lumber for sugar and molasses from the West Indies which was used to manufacture rum in Scotland.
Johnston was a director of the Bank of New Brunswick and a port warden for the harbour at Saint John.
His son Hugh Johnston, Jr. also served in the New Brunswick assembly.