Achille Pierre Dionis du Séjour

Achille Pierre Dionis du Séjour (January 11, 1734 – August 22, 1794) was a French astronomer and mathematician.

[1] Dionis du Séjour was born in Paris and was a distant relative of surgeon and anatomist Pierre Dionis.

He served as an advisor to parliament before he was appointed to the French Academy of Sciences in 1765.

[2] He was appointed to the Paris group for the Estates-General of 1789 and was one of the 47 who joined the Estates of the Realm that year.

Dionis du Séjour died in Vernou-la-Celle-sur-Seine.