Arnoldus Vanderhorst (/vænˈdrɑːs/; March 21, 1748 – January 29, 1815) was an American military officer and planter.

Born in Christ Church Parish, Vanderhorst took up planting at his plantation on the eastern half of Kiawah Island in the Lowcountry.

After his service in the state Senate, Vanderhorst was elected mayor of Charleston for two terms.

During his administration, Vanderhorst pressed the legislature for the revision of the criminal code because the sentences were so harsh that jurors would grant acquittal.

Papers of the Vanderhorst family are held at the South Carolina Historical Society[2] and Bristol Archives.