(b. ca. 1695, Pozsony, d. 1763, Lisboa)
Carlos Mardel, born Martell Károly in Pozsony (now Bratislava, German: Pressburg), Hungarian-born Portuguese military officer, engineer, and architect, active in Portugal. He is primarily remembered for his role in the reconstruction effort after the 1755 Lisbon earthquake.
Mardel first came to Portugal in 1733, as a sergeant-major of engineering for a Portuguese infantry. By 1735, he had become the managing architect of the Águas Livres Aqueduct. In this project, he personally designed and oversaw the construction of the Amoreiras Monumental Arch and the Mãe d'Água Water Reserve. In 1747, owing to his work on the Águas Livres water system, Mardel was appointed Architect of the Royal Household and of the Ancient Military Orders.
Following the 1755 Lisbon earthquake, Mardel was one of the primary architects responsible for the city's reconstruction, alongside Eugénio dos Santos (1711-1760) and Manuel da Maia (1677-1768). His roofing designs became a staple of the city's reconstruction.
In 1759, Mardel began construction on a country manor in Oeiras for Sebastiao José de Carvalho e Melo, the prime-minister at the time for King Joseph I of Portugal. The palace, known as the Palace of the Marquis of Pombal, is considered one of his main works.