| Costanzo Ciano | |
| Order2: | President of the Chamber of Deputies |
| Term Start2: | 28 April 1934 |
| Term End2: | 2 March 1939 |
| Predecessor2: | Giovanni Giuriati |
| Successor2: | Office abolished |
| Order1: | President of Chamber of Fasces and Corporations |
| Term Start1: | 23 March 1939 |
| Term End1: | 26 June 1939 |
| Predecessor1: | Office established |
| Successor1: | Dino Grandi |
| Birth Date: | 1876 8, df=y |
| Birth Place: | Livorno, Italy |
| Death Place: | Lucca, Italy |
| Nationality: | Italian |
| Profession: | Naval commander |
| Party: | National Fascist Party |
Costanzo Ciano, 1st Count of Cortellazzo (pronounced as /it/; 30 August 1876 – 26 June 1939) was an Italian naval officer and politician. He was the father of Galeazzo Ciano.
Born at Livorno, he was the son of Raimondo Ciano and his wife, Argia Puppo. He entered the Livorno Naval Academy in 1891 and was commissioned an officer five years later. In 1901, he became Ship-of-the-Line Lieutenant (tenente di vascello) and took part in the Italo-Turkish War of 1911–1912.
In 1915, before the entrance of Italy to the First World War, he was a capitano di corvetta (lieutenant commander) and was assigned to serve in Cirenaica.
After his return to Italy, he operated at the command of fast MAS units and received a gold medal for military value for a famous action in Bakar Harbour in Croatian Littoral, which was later celebrated by the poet Gabriele D'Annunzio, who had also participated.
Ciano was promoted to the rank of capitano di vascello (captain) at the end of the war.
Ciano's ardent nationalism drew him into fascism. He became leader of the Livorno fascio and participated in the March on Rome in October 1922.[1]
On 31 October 1919, he assumed the post of Undersecretary of State for the Regia Marina and was Commissioner for the Merchant Navy. On 9 November 1923, he was appointed rear admiral in the Naval Reserve. In 1928, he was ennobled by King Victor Emmanuel III as Conte di Cortellazzo. He was the president of the Italian Chamber of Deputies from 1934 until his death, which occurred at Ponte a Moriano in 1939.