Ahmad II ibn Ali (13 April 1862 – 19 June 1942) (Tunisian Arabic: أحمد باي بن علي باي, ʾAḥmad Bāy bin ʿAlī Bāy), commonly known as Ahmed Bey, was the ruler of Tunisia from 11 February 1929 until his death. He was the son of Ali Muddat ibn al-Husayn.
He was born in the Dar al-Taj Palace at La Marsa. On 14 January 1928 he became the Bey al-Mahalla (crown prince) of Tunis, and thus the lieutenant-general of the Beylical Army, and became bey upon the death of his cousin Muhammad VI al-Habib.
A year after his accession, in May 1930, a International Eucharistic Congress was convened in Carthage to celebrate the centenary of the French conquest of Algeria. It was the first such congress held in Africa, and the first in a Muslim-majority country. Ahmed Bey reluctantly agreed to serve as Honorary President of the Congress, which was partly paid for with 2 million francs worth of funds from the Tunisian government, raised in taxes on Tunisia's Muslim population. The event, with some participants dressed as Crusaders and others using it as a platform for speeches hostile to Islam, caused a furore in the Tunisian national movement. The nationalist newspaper La Voix du Tunisien ('The Tunisian Voice') called on the Bey to resign his Honorary Presidency and for other officials to dissociate themselves from the event and members of the Destour Party claimed that the Bey's involvement demonstrated his subservience to the French and abandonment of the defence of his people's interests.
In 1940 the new Vichy regime in France led to the appointment of a new Resident General, Admiral Jean-Pierre Esteva who began pressing Ahmed Bey to implement Vichy anti-Jewish legislation. Article 9 of the French law of 3 October 1940 decreed that the anti-Jewish laws were applicable in the protectorate territories of the French Republic, including Tunisia.