Abdülaziz I or Abd Al-Aziz, His Imperial Majesty (Ottoman Turkish: `Abdü´l-Âzīz-i evvel عبد العزيز) (February 9/18 1830 – 4 June 1876) was the 32nd Sultan of the Ottoman Empire and reigned between 25 June 1861 and 30 May 1876. He was the son of Sultan Mahmud II and succeeded his brother Abdülmecid I in 1861.

Born at the Eyüp Palace, Constantinople, on 9/18 February 1830, Abdülaziz received an Ottoman education but was nevertheless an ardent admirer of the material progress that was made in the West. He was interested in literature and was also a classical music composer. Some of his compositions have been collected in the album "European Music at the Ottoman Court" by the London Academy of Ottoman Court Music.

His parents were Mahmud II and Valide Sultan Pertevniyal ("Partav - Nihal") (1812 – 1883), originally named Bezime, a Vlach. He was a quarter French. In 1868 Pertevniyal was living in the Dolmabahçe Palace. That year Abdülaziz led the visiting Eugénie de Montijo, Empress of France, to see his mother. Pertevniyal perceived the presence of a foreign woman within her quarters of the seraglio as an insult. She reportedly slapped Eugénie across the face, almost resulting in an international incident. The Pertevniyal Valide Sultan Mosque was built under the patronage of his mother. The construction work began in November 1869 and the mosque was finished in 1871. His paternal grandparents were Sultan Abdul Hamid I and Sultana Naksh-i-Dil Haseki. Several accounts identify his paternal grandmother with Aimée du Buc de Rivéry, a cousin of Joséphine de Beauharnais. Pertevniyal was a sister of Hoshiar (Khushiyar), third wife of Ibrahim Pasha of Egypt. Hoshiar and Ibrahim were the parents of Isma'il Pasha.

Between 1861 and 1871, the Tanzimat reforms which began during the reign of his brother Abdülmecid I were continued under the leadership of his chief ministers, Keçecizade Mehmet Fuat Pasha and Mehmed Emin Aali Pasha. New administrative districts (vilayets) were set up in 1864 and a Council of State was established in 1868. Public education was organized on the French model and Istanbul University was reorganized as a modern institution in 1861.

Abdülaziz cultivated good relations with the Second French Empire and the British. In 1867 he was the first Ottoman sultan to visit Western Europe; his trip included a visit to England, where he was made a Knight of the Garter by Queen Victoria and shown a Royal Navy Fleet Review with Ismail of Egypt. He travelled by a private rail car, which today can be found in the Rahmi M. Koç Museum in Istanbul. His fellow Knights of the Garter created in 1867 were Charles Gordon - Lennox, 6th Duke of Richmond, Charles Manners, 6th Duke of Rutland, Henry Somerset, 8th Duke of Beaufort, Prince Arthur, Duke of Connaught and Strathearn, Franz Joseph I of Austria and Alexander II of Russia.

In 1869, Abdülaziz received visits from Eugénie de Montijo, Empress consort of Napoleon III of France and other foreign monarchs on their way to the opening of the Suez Canal. The Prince of Wales, the future Edward VII of the United Kingdom, twice visited Constantinople.

By 1871 both ʿAlī Pasha and Fuʿād Pasha were dead. The Second French Empire, his Western European model, had been defeated in the Franco - Prussian War by the North German Confederation under the leadership of the Kingdom of Prussia. In foreign policy, Abdülaziz turned to the Russian Empire for friendship, as turmoil in the Balkan provinces continued. In 1875, the Herzegovinian rebellion was the beginning of further unrest in the Balkan provinces. In 1876, the April Uprising saw insurrection spreading among the Bulgarians. Ill feeling mounted against Russia for its encouragement of the rebellions.

The crop failure of 1873, the sultan's lavish expenditures for the Ottoman Navy and the new palaces which he built, and the mounting public debt also heightened public discontent. Abdülaziz was deposed by his ministers on 30 May 1876; his death at Feriye Palace in Constantinople a few days later was attributed to suicide at the time, Although in Sultan Abdulhamid II's recently surfaced memoirs, the event is described as an assassination by the order of Huseyin Avni and Mithat Pasha, when Sultan Murad V began to show signs of paranoia, madness and continuous feinting and vomiting even on the day of his coronation and threw himself to a pool yelling at his guards to protect his life. They were afraid the public would become outraged and revolt to bring the former Sultan back, so in a few days, on 4 June 1876, they arranged Sultan Abdülaziz to kill himself with a scissors, cutting his two wrists at the same time. It was unclear how the Sultan got hold of a scissors in the tower prison cell he was imprisoned in, how he managed to cut two wrists at once and no autopsy was allowed afterwards. But the event was recorded as suicide officially and he was buried in Istanbul.

The biggest achievement of Abdülaziz was to modernize the Ottoman Navy. In 1875, the Navy had 21 battleships and 173 warships of other types, ranking as the third largest navy in the world after the British and French navies.

He established the first Ottoman railroad network and Sirkeci Train Station in Constantinople, terminus of the Orient Express.

Impressed by the museums in London, Paris and Vienna, he established the Istanbul Archaeology Museum.

Under Abdülaziz's reign, Turkey's first postage stamps were issued in 1863, and Turkey joined the Universal Postal Union in 1875 as a founding member.

He was made the 756th Knight of the Order of the Garter in 1867 and the 127th Grand Cross of the Order of the Tower and Sword.

Ten children survived him. He married firstly at the Dolmabahçe Palace in Constantinople in 1856 to Georgian HH Dürrünev Kadın Efendi (Batumi, 15 March 1835 - Constantinople, Üsküdar, Çamlıca Palace, 4 December 1892), and had three children. He married secondly at the Dolmabahçe Palace in 1861 to HH Edâdil Kadın Efendi (1845 - Dolmabahçe Palace, 12 December 1875), and had one child. He married thirdly in 1872 to Circassian HH Gevherin Nedaxe Kadın Efendi (Caucasus, 8 July 1856 - Ortaköy Palace, Ortaköy, Constantinople, 20 September 1894), and had one child. He married fourthly at the Dolmabahçe Palace, Constantinople, on 21 September 1866 to Georgian HH Hayranidil Kadın Efendi (Kars, 2 November 1846 - Ortaköy Palace, Constantinople, 26 November 1898), and had two children. He married fifthly at the Dolmabahçe Palace, in 1868 to Georgian HH Nesherek (Nesrin) Haseki Kadın Efendi (Tbilisi, 1848 - 11 June 1876 Ortaköy Palace, Istanbul), and had three children. He married sixthly to Yıldız (Gözde), sister of HH Safinaz Kadın Efendi, a wife of Sultan Abdul Hamid II, and had two children.