Faisal II (Arabic: الملك فيصل الثاني, romanized: al-Malik Fayṣal al-thānī; 2 May 1935 – 14 July 1958) was the last King of Iraq. He reigned from 4 April 1939 until July 1958, when he was killed during the 14 July Revolution. This regicide marked the end of the thirty-seven-year-old Hashemite monarchy in Iraq, which then became a republic.

The only son of King Ghazi and Queen Aliya of Iraq, Faisal acceded to the throne at the age of three after his father was killed in a car crash. A regency was set up under his uncle Prince 'Abd al-Ilah. In 1941, a pro-Axis coup d'état overthrew the regent. The British responded by initiating an invasion of Iraq a month later and restored 'Abd al-Ilah to power. During the Second World War, Faisal was evacuated along with his mother to the United Kingdom. There, he attended Harrow School alongside his cousin Hussein, the future King of Jordan. The regency ended in May 1953 when Faisal came of age.

The overthrow of the Egyptian monarchy in 1952 and the formation of the United Arab Republic in February 1958 only provided impetuses to ideas of a revolution. The Hashemite Arab Federation was formed between Iraq and Jordan in February 1958 with Faisal as its head, which did not quell widespread opposition. In July 1958, a group of Royal Iraqi Army officers led by Abdul-Karim Qasim mounted a coup d'état and overthrew the monarchy. Faisal was executed along with numerous members of his family in the process at the Al-Rehab Palace massacre on 14 July, 1958.

Faisal was the only son of King Ghazi of Iraq and his wife, Queen Aliya, second daughter of 'Ali bin Hussein, King of the Hejaz and Grand Sharif of Mecca. Faisal's father was killed in a mysterious car crash when he was three years old; his father’s first cousin, Prince 'Abd al-Ilah, served as regent until Faisal came of age in 1953. He suffered from asthma.

Faisal's childhood coincided with the Second World War, in which the Hashemite Kingdom of Iraq was formally allied with the British Empire and the Allies. In April 1941, his first cousin once removed 'Abd al-Ilah was briefly deposed as Regent by a military coup d'état which aimed to align Iraq with the Axis powers. The 1941 coup in Iraq soon led to the Anglo-Iraqi War. German aid proved insufficient, and the Regent 'Abd al-Ilah was restored to power by a combined Allied force composed of the Jordanian Arab Legion, the Royal Air Force and other British units. Iraq resumed its British ties, and at the end of the war joined the United Nations.

During his early years, Faisal was tutored at the Royal Al-Rehab Palace with several other Iraqi boys. During the Second World War, he lived for a time with his mother at Grove Lodge at Winkfield Row in Berkshire in England. Faisal attended Sandroyd School then Harrow School with his paternal second cousin Prince Hussein, later to become King Hussein of Jordan. The two boys were close friends, and reportedly planned early on to merge their two realms, to counter what they considered to be the "threat" of Communism and left-leaning variants of pan-Arab nationalism. Recently, 143 drawings by Faisal using either pencil or crayon were put on display at Iraq's National Archives depicting backdrops of the war he lived through. These include drawings of aircraft, bombs, killer robots, and extreme fighting on both land and sea and drawings also depicting peaceful subjects, including landscapes, birds, and buildings, as well as maps of Europe and North Africa. These drawings offered a look into his mind during the chaotic time.

In 1952, at age 17, Faisal began plans to visit the United States and its many development projects such as agriculture, power projects, canal systems, and land reclamation schemes. Of particular interest to the King were the irrigation projects as Faisal would later tell the New York press that those were “very much needed in our country."

On 12 August, 1952, Faisal began the five-week tour and, along with Regent 'Abd al-Ilah, arrived at 11 AM, on the Hudson River on the RMS Queen Mary and were given a tour around the United Nations Headquarters in Manhattan. The next day, Faisal went on a tour of the Empire State Building and after arriving at City Hall for a reception with Mayor Vincent R. Impellitteri, he famously went to attend a game held at Ebbets Field. The visit was covered by many news outlets nationwide that many forgot Faisal's original motives for the visit. He would also famously be on the side of the Brooklyn Dodgers but reportedly could not tell the difference between them and the other team, the New York Giants, until one of his aides told him that the team's names are written on the players' clothes.