| Theodoros Deligiannis | |
| Office: | Prime Minister of Greece |
| Term Start: | 19 April 1885 |
| Term End: | 30 April 1886 (o.s.) |
| Predecessor: | Charilaos Trikoupis |
| Successor: | Dimitrios Valvis |
| Term Start1: | 24 October 1890 |
| Term End1: | 18 February 1892 |
| Predecessor1: | Charilaos Trikoupis |
| Successor1: | Konstantinos Konstantopoulos |
| Term Start2: | 31 May 1895 |
| Term End2: | 18 April 1897 |
| Predecessor2: | Nikolaos Deligiannis |
| Successor2: | Dimitrios Rallis |
| Term Start3: | 24 November 1902 |
| Term End3: | 14 June 1903 |
| Predecessor3: | Alexandros Zaimis |
| Successor3: | Georgios Theotokis |
| Term Start4: | 17 December 1904 |
| Term End4: | 9 June 1905 |
| Predecessor4: | Georgios Theotokis |
| Successor4: | Dimitrios Rallis |
| Birth Date: | April 1826[1] |
| Birth Place: | Kalavryta, Greece |
| Death Place: | Athens, Greece |
| Party: | National Party |
| Relatives: | Nikolaos Deligiannis (cousin once removed) |
Theodoros Deligiannis (died 1905) was a Greek politician, minister and member of the Greek Parliament, who served as Prime Minister of Greece five times from 1885 until his assassination.
He led the National Party, which, alongside the New Party led by his primary political opponent, Charilaos Trikoupis, formed the two-party system of the time.
He was born at Kalavryta. He studied law in Athens, and in 1843 entered the Ministry of the Interior, of which department he became permanent secretary in 1859. In 1862, on the deposition of King Otto, he became minister for foreign affairs in the provisional government. In 1867, he was Greek Minister at Paris. On his return to Athens he became a member of successive cabinets in various capacities, and rapidly collected a party around him consisting of those who opposed his great rival, Charilaos Trikoupis. He eventually became the leader of the National Party.
In the so-called Oecumenical Ministry of 1877 he voted for war with Turkey. On that ministry's fall, Diligiannis entered the cabinet of Koumoundouros as minister for foreign affairs. He was a representative of Greece at the Berlin Congress in 1878. From this time forward, and particularly after 1882, when Trikoupis again came into power at the head of a strong party, the duel between these two statesmen was the leading feature of Greek politics.
Diligiannis first formed a cabinet in 1885; but his warlike policy, the aim of which was, by threatening Turkey, to force the Great Powers to make concessions in order to avoid the risk of a European war, ended in failure. For the powers, in order to stop his excessive armaments, eventually blockaded the Piraeus and other ports, and this brought about his downfall. He returned to power in 1890, with a radical programme, but his failure to deal with the financial crisis produced a conflict between him and the king, and his disrespectful attitude resulted in his summary dismissal in 1892. Diligiannis evidently expected the public to side with him; but at the elections he was badly beaten.
In 1895, however, he again became prime minister, and was at the head of affairs during the Cretan Revolt (1897–1898) and the opening of the Greco-Turkish War (1897). The easy defeat which ensued caused his fall from power in April 1897. Diligiannis himself had been led into the disastrous war policy to some extent against his will. The king again dismissed him from office when he declined to resign. Diligiannis kept his own seat at the election of 1899, but his following dwindled to small dimensions. He quickly recovered his influence, however, and he was again president of the council and minister of the interior.
On 13 June 1905, he was assassinated in revenge for the rigorous measures taken by him against gambling houses. His attacker, a professional gambler named Antonios Gherakaris, stabbed him with a dagger in the abdomen as he was entering the parliament. The incident took place at 5pm; an emergency operation failed to stop his internal bleeding and Diligiannis died at 7.30pm.