This photo was found with (but not in) an envelope containing seven photos of European royals, all but two of which have been positively identified (one of them here by Evargalo).
Below is a photo of the back. The card measures approximately 4 inches (10.16cm) by 2.5 inches (6.35cm) while the photo is about 3 inches by 2 inches.
The photographic studio indicated on the back belonged to Emile Desmaisons (1812-80) and the photo probably dates from 1866 as
Il a effectué des reproduction photographiques de lithographies. - Ateliers à Paris : 5 rue des Grands Augustins (de 1861 à 1862) et 22 rue de l'Arbre Sec (1866)
Translation: He made photographic reproductions of lithographs. - Workshops in Paris: 5 rue des Grands Augustins (from 1861 to 1862) and 22 rue de l'Arbre Sec (1866)
Also, '1866' can be seen on the right side of the photo (near the man's left arm).
To my (very untutored) eye, the hat looks Turkish. I'm hoping the decorations / medals will enable someone to identify this man, or at least provide some clues as to who he might be.