The Chadian-Libyan conflict is a state of sporadic warfare events in Chad between 1978 and 1987, between Libyan and Chadian forces.

Libya had been involved in Chad's internal affairs prior to 1978 and before even Muammar al-Gaddafi's rise to power in Libya in 1969, beginning with the extension of the Chadian Civil War to northern Chad in 1968.

The conflict is marked by a series of four separate Libyan interventions in Chad, taking place in 1978, 1979, 1980–1981 and 1983–1987.

In all of these occasions Gaddafi has the support of a number of factions participating in the civil war, while Libya's opponents find the support of the French government, which intervenes militarily to save the Chadian government in 1978, 1983 and 1986.The military pattern of the war delineate itself already in 1978, with the Libyans providing armor, artillery and air support and their Chadian allies the infantry, which assume the bulk of the scouting and fighting.

This pattern is radically to change in 1986, towards the end of the war, when all Chadian forces unite in opposing the Libyan occupation of northern Chad with a degree of unity that has never been seen before in Chad.

This deprives the Libyan forces of their habitual infantry, exactly when they find themselves confronting a mobile army, well-provided now with anti-tank and anti-air missiles, thus canceling the Libyan superiority in firepower.

What follows is the Toyota War, in which the Libyan forces are routed and expelled from Chad, putting an end to the conflict.Regarding the reasons behind Gaddafi's involvement with Chad, the initial reason stands in his ambition to annex the Aouzou Strip, the northernmost part of Chad that he claims as part of Libya on the grounds of an unratified treaty of the colonial period.

In 1972 his goals become, in the evaluation of the historian Mario Azevedo: The creation of a client state in Libya's "underbelly", an Islamic republic modeled after his jamahiriya, that willl maintain close ties with Libya, and secure his control over the Aouzou Strip; expulsion of the French from the region, and the use of Chad as a base to expand his influence in Central Africa.