Much of the history of Algeria has taken place on the fertile coastal plain of North Africa, which is often called the Maghreb. North Africa served as a transit region for people moving towards Europe or the Middle East, thus, the region's inhabitants have been influenced by populations from other areas, including the Carthaginians, Romans, and Vandals. The region was conquered by the Muslims in the early 8th century AD, but broke off from the Umayyad Caliphate after the Berber Revolt of 740. During the Ottoman period, Algeria became an important state in the Mediterranean sea which led to many naval conflicts. The last significant events in the country's recent history have been the Algerian War and Algerian Civil War.

Evidence of the early human occupation of Algeria is demonstrated by the discovery of 1.8 million year old Oldowan stone tools found at Ain Hanech in 1992. In 1954 fossilised Homo erectus bones were discovered by C. Arambourg at Ternefine that are 700,000 years old. Neolithic civilization (marked by animal domestication and subsistence agriculture) developed in the Saharan and Mediterranean Maghrib between 6000 and 2000 BC. This type of economy, richly depicted in the Tassili n'Ajjer cave paintings in southeastern Algeria, predominated in the Maghrib until the classical period.

Numidia (Berber: Inumiden; 202–40 BC) was the ancient kingdom of the Numidians located in northwest Africa, initially comprising the territory that now makes up modern-day Algeria, but later expanding across what is today known as Tunisia, Libya, and some parts of Morocco. The polity was originally divided between the Massylii in the east and the Masaesyli in the west. During the Second Punic War (218–201 BC), Masinissa, king of the Massylii, defeated Syphax of the Masaesyli to unify Numidia into one kingdom. The kingdom began as a sovereign state and later alternated between being a Roman province and a Roman client state.

Numidia, at its largest extent, was bordered by Mauretania to the west, at the Moulouya River, Africa to the east (also exercising control over Tripolitania), the Mediterranean Sea to the north, and the Sahara to the south. It was one of the first major states in the history of Algeria and the Berbers.

By 112 BC, Jugurtha resumed his war with Adherbal. He incurred the wrath of Rome in the process by killing some Roman businessmen who were aiding Adherbal. After a brief war with Rome, Jugurtha surrendered and received a highly favourable peace treaty, which raised suspicions of bribery once more. The local Roman commander was summoned to Rome to face corruption charges brought by his political rival Gaius Memmius. Jugurtha was also forced to come to Rome to testify against the Roman commander, where Jugurtha was completely discredited once his violent and ruthless past became widely known, and after he had been suspected of murdering a Numidian rival.

War broke out between Numidia and the Roman Republic and several legions were dispatched to North Africa under the command of the Consul Quintus Caecilius Metellus Numidicus. The war dragged out into a long and seemingly endless campaign as the Romans tried to defeat Jugurtha decisively. Frustrated at the apparent lack of action, Metellus' lieutenant Gaius Marius returned to Rome to seek election as Consul. Marius was elected, and then returned to Numidia to take control of the war. He sent his Quaestor Sulla to neighbouring Mauretania in order to eliminate their support for Jugurtha. With the help of Bocchus I of Mauretania, Sulla captured Jugurtha and brought the war to a conclusive end. Jugurtha was brought to Rome in chains and was placed in the Tullianum.

Jugurtha was executed by the Romans in 104 BC, after being paraded through the streets in Gaius Marius' Triumph.

The Greek historians referred to these peoples as "Νομάδες" (i.e. Nomads), which by Latin interpretation became "Numidae" (but cf. also the correct use of Nomades). Historian Gabriel Camps, however, disputes this claim, favoring instead an African origin for the term.