Ercole Pietro Manfredi (2 July 1883 – 9 June 1973) was an Italian architect who lived and worked in early twentieth-century Siam (now Thailand).

Born in Turin, Italy, he attended the Albertina Academy of Fine Arts before travelling to Bangkok, where he was one of many Westerners employed by the Siamese government.

At the age of sixteen, he was admitted into the Albertina Academy of Fine Arts, where during his studies he received a first prize in architecture, design, perspective and painting.

[2] In 1912, Manfredi was promoted to a position in the Ministry of the Royal Household, where he worked closely with King Vajiravudh and Prince Narisara Nuvadtivongs.

[3] In 1930, during the period of political turmoil leading up to the abolition of absolute monarchy in the Siamese Revolution of 1932, Manfredi retired from government office.

His government contract had required him "to be able within one year to converse in Siamese in a tolerable way," but he went further and became fluent in both the spoken and written language.

[6] Following the revolution of 1932, rising nationalistic sentiments resulted in a large decline in the role and numbers of Westerners working for the government.

[11] He was also noted to be impulsive and stubborn, often ignoring his wife's sensible advice to do what he wanted, including leaving his official post to pursue archaeology.

"[12] At the age of seventy-five, Manfredi realised his dream project of building a boat; to finance, he had to sell his entire collection of Siamese art.

[15] Manfredi's architectural works involve both Thai and Western designs, which he adapted and developed to suit the local tradition.

Upon his arrival in Bangkok in 1909, Manfredi collaborated with other Italian architects in the construction of Ananta Samakhom Throne Hall, which had begun in 1908 and lasted until 1915.

Manfredi was mainly responsible for the dome and the roof of the building, which was designed in the Italian Renaissance and neoclassical styles and modelled in part after the Basilica of Superga.

[16][19][20] He also contributed to the design and construction of Villa Norasingh (1923–25), now the Thai Khu Fa Building of the Government House, although it is not officially attributed to him.

These include Manfredi Residence (1935) and Asawin Villa (c.1930s), which were influenced by the Bauhaus school and are among the first modernist buildings in Thailand.

They are the marble guardian lions at Wat Benchamabophit and the statue of Jarlet, King Vajiravudh's beloved dog, at Sanam Chandra Palace.

He improved on the mechanics involved in the royal funeral procession and was particularly interested in developing an irrigation system for the country.