Ilham Heydar Oghlu Aliyev (born 24 December 1961) is an Azerbaijani politician who has been the fourth president of Azerbaijan since 2003. He is also the leader of the New Azerbaijan Party since 2005.

The son and second child of former Azerbaijani president Heydar Aliyev, Aliyev became the country's president on 31 October 2003 after a two-month term as the prime minister of Azerbaijan, through a presidential election defined by irregularities shortly before his father's death. He was reelected for a second term in 2008 and was allowed to run in elections indefinitely in 2013, 2018 and 2024 due to the 2009 constitutional referendum, which removed term limits for presidents.

Azerbaijan being oil-rich is viewed to have significantly strengthened the stability of Aliyev's regime and enriched ruling elites in Azerbaijan, making it possible for the country to host lavish international events, as well as engage in extensive lobbying efforts. Aliyev's family have enriched themselves through their ties to state-run businesses. They own significant parts of several major Azerbaijani banks, construction firms and telecommunications firms, and partially own the country's oil and gas industries. Aliyev was named Corruption's 'Person of the Year' by Organized Crime and Corruption Reporting Project in 2012. In 2017, it was revealed that Aliyev and his family were involved in the Azerbaijani laundromat, a complex money-laundering scheme to pay off prominent European politicians to deflect criticism of Aliyev and promote a positive image of his regime.

Aliyev is widely considered a dictator, leading an authoritarian government with no free and fair elections, endemic corruption, and serious human rights violations. Despite being a secularist, Aliyev's rule has seen more Sunnification efforts and suppression of Shia Islamists. His regime is known for harassing journalists and non-governmental organizations, and carried ethnic cleansing of Nagorno-Karabakh. The Nagorno-Karabakh conflict continued during Aliyev's presidency and devolved into a full-scale war in 2020 in which Azerbaijan regained control over the Armenian-occupied territories surrounding Nagorno-Karabakh that were lost during the First Nagorno-Karabakh War, as well as a part of Nagorno-Karabakh region itself. Then, in the fall of 2023, Azerbaijan initiated a military offensive in the disputed region which ended with the surrender of the self-declared Republic of Artsakh and mass displacement of more than 100,000 ethnic Armenians in Nagorno-Karabakh. Aliyev and his government have faced accusations of ethnic cleansing and war crimes in the aftermath of this military operation.