Xavier Pascal Coste (26 November 1787, Marseille - 8 February 1879) was a French architect. His father was one of the leading joiners in Marseille. Showing intellectual and artistic promise, Pascal began his studies in the studio of Penchaud, architect of the d矇partement and the municipalit矇. In 1814, he was received into the ?cole des Beaux-Arts in Paris. His time in Paris was a pivotal one in his life - there he met the geographer Edme Fran癟ois Jomard, who put him in touch with the viceroy of Egypt, Mehmet Ali, who took Coste on as his architect in 1817.

In 1825 Coste returned to France with an impressive series of drawings of the architecture of Cairo, but he soon went to Egypt once again at Mehmet Ali's request, where Mehmet Ali made him chief engineer for Lower Egypt. Coste remained there for four years, during which time he accumulated many sketches, but he found the Egyptian climate difficult and returned to France in 1829. There he became a professor of architecture at the ?cole des Beaux-Arts in Paris, thanks to the links he had kept up with Penchaud. He remained in this post until 1861, when he was one of the founder members of the intellectual centre known as the Ath矇n矇e.

In parallel with these activities he travelled around France and to Germany, Belgium and Tunisia and produced several authoritative works on architecture - his Architecture arabe (1827) earned him a place on the French king's embassy to the Shah of Iran. In Iran Coste and the painter Eug癡ne Flandin were authorised to visit the ruins of Ecbatana, Bishtun, Taq-e Bostan, Sarpol-e Zahab, Pasargadae and Persepolis, where he made many sketches. On his return via Baghdad, he saw the ruins of Seleucia, Ctesiphon and Babylon. He continued via Nineveh, to which the archaeologist Paul ?mile Botta was also travelling to begin his excavations.