Vallaury (also spelled Vallauri) was born in 1850 into a Levantine family in Istanbul. His father, Francesco Vallauri, was a renowned pastry chef from Nice, highly respected in court circles. Vallaury's nationality is not definitively known; he was born in modern day Istanbul and, as his family emigrated from Nice at a time when the city was still under piedmontese rule, he is assumed to have been of both Franco-Levantine or Italian-Levantine extraction due to his affinity to both cultures.
Between 1869 and 1878, Vallaury lived in Paris, France, where he studied architecture at the École nationale supérieure des Beaux-Arts. Returning to Istanbul in 1880, he met Osman Hamdi Bey, who was at that time curator of the newly established Imperial Museum (Turkish: Müze-i Humayun - now the Istanbul Archaeology Museum), during an exhibition of his relief drawings of various architectural monuments. The two artists worked closely together 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, now the Mimar Sinan Fine Arts University) in Turkey on January 1, 1882, Alexandre Vallaury started working in the architecture department. He lectured at the school for 25 years until his retirement in 1908.
Following the 1894 Istanbul earthquake, he was appointed to work on various commissions for city planning. Remembered by Osman Bey as the "City Architect" (Mimar-ı Şehir), Vallaury was almost invariably the architect chosen by the upper echelons of Ottoman high officials and French business circles while he worked at the School of Fine Arts. On some of these projects, he worked with the Italian architect Raimondo D'Aronco, the chief architect at the sultan's palace.
In 1896, he was awarded France's Legion of Honour to go with many other medals and awards from the French and Ottoman governments.