Aoun enrolled at the Lebanese American University to pursue a bachelor's degree in political science and international affairs, which he earned in 2007.

In 1990, Aoun served as a lieutenant in the Lebanese Army's Commando Regiment (Arabic: فوج المغاوير) under leader Bassam Gergi at the Adma barracks.

In the 1990 Elimination War, two hundred commandos loyal to General Michel Aoun were trapped in their base in Adma wa Dafneh by Samir Geagea’s Lebanese Forces militia (LF) until a truce was arranged to allow their evacuation.

[13] Following protests in Lebanon and the political deadlock, General Aoun spoke out on 8 March 2021 criticising the Lebanese liquidity crisis and its impact on the military.

[18] In December 2022, a five-nation group was formed by the Doha envoy which involved the United States, France, Saudi Arabia, and Egypt to hold talks and resolve the presidential vacancy in Lebanon in which most countries affirmed their support for Aoun's election.

[20] On 9 January 2025 opposition groups including the Kataeb party, the Renewal Bloc, and the Lebanese Forces issued a joint statement in support of Aoun.

[22] In his inaugural address, he vowed to fight the mafias, drug trafficking, interference in the justice system, corruption, poverty, and sectarianism.

[31] Salam and Aoun's election is seen as a manifestation of Hezbollah's diminished influence in Lebanese politics, partly due to the group's military and financial losses in the conflict with Israel and the fall of the Assad regime in Syria.