He was born 1850 into a Levantine family in Istanbul. His father, Francesco Vallaury, was a renowned pastrycook, respected much in the court circles. The nationality of Alexander is not exactly known, however, it is assumed that he is of French extraction due to his affinity to French culture.
Alexander Vallaury spent his time between 1869 and 1878 in Paris, France, where he studied architecture at the École nationale supérieure des Beaux-Arts. Returned 1880 to Istanbul, he met Osman Hamdi Bey, who was at that time curator of the newly established "Empire Museum" (Turkish: Müze-i Humayun), which is today Istanbul Archaeology Museum, during an exhibition of his relief drawings of various architectural monuments. The two artists worked closely in the fields of archaeology, museum work and education in fine arts.
Following the foundation of the first School of Fine Arts (Turkish: Sanayi-i Nefise Mektebi) in Turkey on January 1, 1882, Alexander Vallaury was appointed with the establishment of the architecture department of the school, which is today Mimar Sinan University of Fine Arts. He lectured 25 years long at the school until his retirement in 1908.
In 1896, he was awarded with the French order Légion d'honneur together with many other medals and awards from the French and Ottoman governments. Following the 1894 Istanbul earthquake, he was appointed to work in various commissions for city planning. Remembered by Osman Bey as the "City Architect" (Mimar-ı Şehir), Vallaury became the architect invariably chosen by the upper echelons of Ottoman high officials and French business circles during the time he was an instructor at the School of Fine Arts. On some of the projects he fulfilled for these circles, he was joined by the Italian architect Raimondo Tommaso D'Aronco, the chief architect at the sultan's palace.
Vallaury combined the traditional Ottoman architecture with the elements of Beaux-Arts architecture in his designs of buildings made for the members of the palace and for the high officials in Istanbul. His architectural approach shows variety in a broad spectrum from Islamic-Ottoman synthesis to Neoclassical architecture. He used also motifs of international Orientalism at some Neo-Renaissance and Neo-Ottoman elements. Particularly in his buildings of Neo-Ottoman design, Neo-Baroque and Art Nouveau details take place.
- Café Lebon (from 1940 on Café Marquise - Markiz Pastanesi) (1880) - Beyoğlu, Istanbul
- Décugis house (today Galata Antique Hotel) (1881) - Şişhane, Istanbul
- Hotel Pera Palace (1881-1891) -Şişhane, Istanbul
- Hidayet Mosque (1887) - Eminönü, Istanbul
- Imperial Ottoman Bank Headquarters (1890) - Karaköy, Istanbul
- Main building of Istanbul Archaeology Museum (1891-1907) - Sultanahmet, Istanbul
- Imperial Military School of Medicine (later Haydarpasa Lycee, today Marmara University, Faculty of Law) (with Raimondo Tommaso D'Aronco) (1893-1902) - Haydarpaşa, Istanbul
- Union Francaise building (1896) - Şişhane, Istanbul
- Ottoman Public Debt Administration building (today Istanbul Lycee) (1897) - Cağaloğlu, Istanbul
- Prinkipo Palace (Büyükada Greek Orphanage) (1898-1899) - Büyükada, Istanbul
- Hezaren Han (1902) - Karaköy, Istanbul
- Omer Abed Han (1902) - Karaköy, Istanbul
- Osman Reis Mosque (1903-1904) - Sarıyer, Istanbul
- Afif Pasha waterfront house (Muhayyes Yalı), (circa 1910) - Yeniköy, İstanbul