Count Olympe-Clemente-Alexandre-Auguste Aguado de las Marismas (3 February 1827 – 25 October 1894) was a Franco-Spanish photographer and socialite, active primarily in the 1850s and 1860s.
One of several early photographers who learned the practice from Gustave Le Gray, Aguado pioneered a number of photographic processes, including carte de visite photographs and photographic enlargement processes.
He was also a founding member of the influential French Photographic Society in 1854.