The Toyota War (Arabic: حرب التويوتا, romanized: Ḥarb al-Tūyūtā, Harb-el-Touyouta, French: Guerre des Toyota), also known as the Great Toyota War, was the last phase of the Chadian–Libyan War which took place in 1987 in Northern Chad and on the Chad-Libya border. It takes its name from the Toyota pickup trucks, primarily the Toyota Hilux and the Toyota Land Cruiser, which were used to provide mobility for Chadian troops as they fought against the Libyans, and as technicals. The 1987 war resulted in a heavy defeat for Libya, which, according to American sources, lost one tenth of its army, with 7,500 men killed and US$1.5 billion worth of military equipment destroyed or captured. Chadian forces suffered 1,000 deaths.

The war began with the Libyan occupation of northern Chad in 1983, when Libya's leader Muammar Gaddafi, refusing to recognise the legitimacy of the Chadian President Hissène Habré, militarily supported the attempt by the opposition Transitional Government of National Unity (GUNT) to overthrow Habré. The plan was foiled by the intervention of France which, first with Operation Manta and later with Operation Epervier, limited Libyan expansion to north of the 16th parallel, in the most arid and sparsely inhabited part of Chad.

In 1986, the GUNT rebelled against Gaddafi, stripping Libya of its main cover of legitimacy for its military presence in Chad. Seeing an occasion to unify Chad behind him, Habré ordered his forces to pass the 16th parallel so as to link up with the GUNT rebels (who were fighting the Libyans in Tibesti) in December. A few weeks later a bigger force struck at Fada, destroying the local Libyan garrison. In three months, combining methods of guerrilla and conventional warfare in a common strategy, Habré was able to retake almost all of northern Chad, and in the following months, inflicted new heavy defeats on the Libyans, until a ceasefire putting an end to the conflict was signed in September. The ceasefire left open the issue of the disputed Aouzou Strip, which was eventually assigned to Chad by the International Court of Justice in 1994.

Since 1983, Chad was de facto partitioned, with the northern half controlled by the rebel Transitional Government of National Unity (GUNT) headed by Goukouni Oueddei and supported on the ground by Libyan forces, while the south was held by the Western-backed Chadian government guided by Hissène Habré. This partition on 16th parallel (the so-called Red Line) into Libyan and French zones of influence was informally recognised by France in 1984, following an accord between France and Libya to withdraw their forces from Chad. The accord was not respected by Libya, which maintained at least 3,000 men stationed in northern Chad.

During the period between 1984 and 1986, in which no major clash took place, Habré greatly strengthened his position thanks to Western support and Libya's failure to respect the Franco-Libyan 1984 agreement. From 1984 onwards, the GUNT also suffered increasing factional tensions, centered on the fight between Goukouni and Acheikh ibn Oumar over the leadership of the organisation. Taking advantage of the GUNT's difficulties, Habré struck a series of accords with smaller rebel factions, which left the GUNT at the beginning of 1986 with only three of the eleven factions that had originally signed the Lagos Accord in 1979. The remaining factions were Goukouni's People's Armed Forces (FAP), Acheikh's armed branch of the Democratic Revolutionary Council (CDR) and that part of the Chadian Armed Forces (FAT) which had maintained its loyalty to Wadel Abdelkader Kamougué.

At the opening of 1987, the last year of the war, the Libyan expeditionary force was still impressive, comprising 8,000 soldiers, 300 tanks, multiple rocket launchers (rocket artillery) and regular artillery pieces, Mi-24 helicopters, and sixty combat aircraft^{[clarification needed]}. These forces did not have a unified command but were divided into an Operational Group South, active in the Tibesti with 2,500 men, and an Operational Group East, centered in Faya-Largeau.

Though formidable, the Libyan military disposition in Chad was marred by serious flaws. The Libyans were prepared for a war in which they would provide ground and air support to their Chadian allies, who would then act as assault infantry, and provide reconnaissance. By 1987, however, Muammar Gaddafi had lost his allies, exposing Libya's inadequate knowledge of the area. Libyan garrisons came to resemble isolated and vulnerable islands in the Chadian Sahara. Also significant was the low morale among the troops, who were fighting in a foreign country, and the structural disorganization of the military of Libya, which was in part induced by Muammar Gaddafi's fear of a military coup against him. This fear led him to avoid the professionalization of the armed forces.

The Libyans also had to deal with the greatly strengthened Chadian National Armed Forces (FANT), which was composed of 10,000 highly motivated soldiers, led by experienced and able commanders, such as Idriss Déby, Hassan Djamous and Head of State Hissène Habré himself. And while FANT previously had no air power, limited mobility, and few anti-tank and anti-aircraft weapons, by 1987, it could count on the French Air Force to keep Libyan aircraft grounded and, most importantly, to provide 400 new Toyota pickups equipped with MILAN anti-tank guided missiles. It is these trucks that gave the name "Toyota War" to this last phase of the Chadian-Libyan conflict.