Alexander Stepanovich Kaminsky was a Russian architect known for his works in the style of late eclecticism from the 1860s to the 1880s. He designed the first building of the Tretyakov Gallery, Tretyakovsky Passage, and numerous private and public buildings in Moscow, as well as the large cathedral of the Nikolai-Ugrish Monastery.

Kaminsky was born in 1829 into a noble family in the Volhynia province. After graduating from the Kyiv gymnasium in 1848, he entered the Imperial Academy of Arts, where he studied under architect Konstantin Ton. As part of his training, he participated in the construction of the Cathedral of Christ the Savior in Moscow, which was overseen by his brother Joseph Kaminsky. From 1857 to 1860, Alexander interned in Rome, where he met P.M. Tretyakov, who purchased several watercolors depicting Roman ruins from him. In 1862, Kaminsky married Tretyakov's sister, Sofia Mikhailovna, and his subsequent career was closely linked to this merchant family. Through the Tretyakovs, he received commissions from many wealthy Muscovites, such as the Botkins, Morozovs, and Konshins.

Kaminsky primarily worked in the style of late eclecticism but also incorporated elements of Russian architecture and Gothic, adapting them to the type of building and the wishes of clients. From 1867 to 1893, he was the senior architect of the Moscow Merchant Society, and from 1885 to 1889, he held the position of architect of the Imperial Moscow Technical School.

His successful career was abruptly interrupted in 1888 after the collapse of a tenement building at the corner of Kuznetsky Bridge and Neglinnaya. Kaminsky was accused of violating safety regulations, which led to a six-week arrest. Five years later, he was forced to leave his position as chief architect of the Moscow Merchant Society, and he was unable to restore his reputation.

Among Kaminsky's notable constructions are the Spaso-Preobrazhensky Cathedral of the Nikolai-Ugrish Monastery, the Kazan Cathedral in the Kazan Monastery of Vyshny Volochyok, and the Alexander Nevsky Cathedral in Yegoryevsk. His last work was the church of St. Seraphim in Sarov, consecrated in 1903.

In Moscow, Kaminsky's works include Tretyakovsky Passage, the facade of the house of Princess Shakhovskaya-Glebova-Streshneva (now "Helikon-Opera"), the residence of Sergey Tretyakov on Gogolevsky Boulevard (now the Russian Cultural Foundation), the Lopatina mansion (now the Embassy of Russia), and others.

Alexander Stepanovich Kaminsky passed away in 1897.