Henrietta Catherine Agnes of Anhalt-Dessau (born 5 June 1744 in Dessau; died 15 December 1799 in Dessau) was a princess of Anhalt-Dessau by birth, Dean of Herford Abbey and by marriage Baroness of Loën.

At the age of six months, she was made a canoness in Herford Abbey; this should provide her for life.

As the oldest sister, Agnes took over the duties of representation at the court in Dessau, until her brother Leopold III married.

From 1795, Agnes and John Jost lived in Dessau and had a keen interest in the social life of the city.

After a visit, she wrote in 1796: In Dessau, the memory of earlier times delighted us: the Loën family proved to be comfortable, trusting relatives and we could remembered our earliest days and hours together in Frankfurt.