Andrew Duncan (1755–1827) was an 18th/19th century Church of Scotland minister who served as Moderator of the General Assembly in 1824.
He was born in 1755 the son of Rev Patrick Duncan, minister of Tibbermore.
In September 1802 he was presented to the congregation of Ratho in West Lothian by his colleague Rev Dr Thomas Randall Davidson of Muirhouse and in March 1803 he translated to this new ministry.
In 1811 Edinburgh University awarded him an honorary Doctor of Divinity.
In 1824 he succeeded Rev Alexander Brunton as Moderator of the General Assembly.