Cipriano Segundo Montesino y Estrada (26 September 1817 – 27 August 1901) was a Spanish civil engineer and politician.

He graduated in civil engineering from the École Centrale Paris in 1837, after returning to Spain upon the death of Ferdinand VII in 1833.

A significant figure in Spain's liberal reforms, he was a founder member of the Royal Academy of Exact, Physical, and Natural Sciences, becoming its president in 1882.

[4] He was also a member of various national and international scientific societies, served as the Director-General of Public Works in Spain, and was awarded the Order of Charles III.

[4] He was a member of the International Commission for the piercing of the isthmus of Suez, and published papers in the Spanish civil engineering journal, Revista de Obras Públicas, on the subject of the canal.