Jacobus Ferdinandus Saey or Jacob Ferdinand Saeys was a Flemish painter who specialized in architectural paintings depicting gallant companies amidst imaginary Renaissance and Baroque palaces and buildings. After starting his career in Flanders, he moved to Vienna, where he worked for the rest of his life.

Jacobus Ferdinandus Saey was born in Antwerp. He was possibly a cousin of the art dealer Jan Saey. He became in 1672–73 an apprentice of the architecture and perspective painter Wilhelm Schubert van Ehrenberg. Some sources state that van Ehrenberg was his uncle. He became a master in the Antwerp Guild of Saint Luke in the guild year 1679–80. He was still recorded in the Antwerp Guild records in 1681. The last record about him in Flanders places him in Mechelen in 1684.

The next record on the artist relates to his marriage with Maria von Risman in Vienna in 1694. He is known to have been active in Vienna for a number of years prior to his marriage. He lived in the Leopoldstadt district of Vienna. He seems to have kept in touch with members of the Flemish community in Vienna. The painter Peter Schubart von Ehrenberg, the son of Saey's master Wilhelm Schubert van Ehrenberg, and the painter Johannes Erasmus de Crefft were the witnesses at his wedding. The Flemish painter Anthoni Schoonjans was one of the godfathers at the baptism of his daughter Antonia Catharina.

He was still recorded in Vienna in 1726. The date and place of his death are not known.