Constantin Angelescu (10 June 1869[1] – 14 September 1948) was a Romanian politician who served as ad interim/acting Prime Minister of Romania for five days, between 30 December 1933 and 3 January 1934.

As Minister of Public Works in the Government of Ion I. C. Brătianu, he was especially charged with the organization of the Romanian military service, with Romania's entry into World War I.

The supporter for the accession to the Triple Entente caused the annoyance of the prime minister who had dismissed him during the establishing of the national union coalition.

In 1917, during the evacuation of the government and king to Iași, Angelescu lived for a short time in Odesa, and then returned to the country.

In January–March 1918 he was appointed as Romania's first plenipotentiary minister in Washington, D.C. Then in 1918, he was the Deputy Chairman of the National Council for Romanian Unity established by Take Ionescu in Paris.

Bratianu improved, and Dr. Angelescu was next to him in the moments after the assassination attempt in 1904 and in the last hours of his life in 1927, when he closely supervised the medical-surgical treatment he had given.

He is one of the members of the Crown Council chaired by Carol II who voted for the cession of Bessarabia and northern Bucovina to the Soviet Union following the ultimatum given to Romania on June 26, 1940.

His daughter Ioana (Jeanne) Angelescu married Ștefan Ghika–Budești, geologist, correspondent member of the Romanian Academy, the son of the architect Nicolae Ghika-Budești.