Agathon Bartholomæus Hansteen (23 September 1812 – 30 April 1895) was a Norwegian priest and politician.
He was born in Moss as a son of merchant Nils Lynge Hansteen (1782–1861) and Severine Petronelle née Clementin.
His brother Christopher Hansteen became a Supreme Court justice.
Following a period as a teacher at Trondhjem Cathedral School, he became vicar in Mo in 1843.
Here, he also served in the municipal council, including a stint as mayor in 1872–1873.