The Kingdom of Matamba (pre-1550–1744) was an African state located in what is now the Baixa de Cassange region of Malanje Province of modern-day Angola. Joined to the Kingdom of Ndongo by Queen Nzinga in 1631, the state had many male and female rulers. It was a powerful kingdom that long resisted Portuguese colonisation attempts, but was integrated into Portuguese Angola in the late nineteenth century.

The first documentary mention of the Kingdom of Matamba is a reference to it giving tribute to the King of Kongo, then Afonso I of Kongo, in 1530. In 1535 Afonso subsequently mentioned Matamba as one of the regions over which he ruled as king in his titles. There is no further information on the kingdom's early history and modern oral traditions do not seem to illuminate this at the present state of research. However, it does not seem likely that Kongo had any more than a light and symbolic presence in Matamba, and its rulers were probably quite independent. Matamba undoubtedly had closer relations with its south southeastern neighbor Ndongo, then a powerful kingdom as well as with Kongo.

During the mid-sixteenth century Matamba was ruled by Ngola Njinga, who received missionaries from Kongo, then a Christian kingdom, dispatched by King Diogo I (1545–1561). Though this ruler received the missionaries and perhaps allowed them to preach, there is no indication that the kingdom converted to Christianity.

The arrival of the Portuguese colonists under Paulo Dias de Novais in Luanda in 1575 altered the political situation as the Portuguese immediately became involved in Ndongo's affairs, and war broke out between Ndongo and Portugal in 1579. Although Matamba played a small role in the early wars, the threat of a Portuguese victory stirred the ruler of Matamba (probably a king named Kambolo Matamba) to intervene. He sent an army to aid Ndongo against the Portuguese, and with these forces, the combined armies were able to defeat and rout Portuguese forces at the Battle of the Lukala in 1590.

In 1618 the Portuguese governor of Angola, Luis Mendes de Vasconcelos, launched a large-scale attack on Ndongo, using newly acquired Imbangala allies. The allied Imbangala, mercenary soldiers from south of the Kwanza River, turned the day and allowed Mendes de Vasconcelos' forces to sack Ndongo's capital and pillage the country. During the following two years, Mendes de Vasconcelos' son João led a detachment of Portuguese and Imbangala forces into Matamba where they did great damage. During this time the Imbangala band of Kasanje deserted the Portuguese and continued a campaign of destruction in Matamba. Thousands of Matamba subjects were killed and thousands more taken to America as slaves. It is during this period, for example, that the ethnonym "Matamba" appears in slave inventories in Spanish America in considerable numbers.

Ndongo continued to suffer attacks from Portuguese forces, and in 1624 King Njinga Mbandi (also known as Nzinga) took over as ruler of that country. She continued the war unsuccessfully against Portugal and was forced to flee the country in 1626 and then again in 1629. During her second flight Njinga entered Matamba and her forces routed the army of Matamba's ruler, “Queen” Mwongo Matamba [sv], capturing her and taking her prisoner. From at least 1631 onward, Njinga made Matamba her capital, joining it to the Kingdom of Ndongo.

The great Ngola Njinga ruled in Matamba from 1624 until her death in 1663. During this time she integrated the country into her domains and thousands of her former subjects who had fled Portuguese attacks with her settled there. She made several wars against Kasanje especially in 1634–5. In 1639 she received a Portuguese peace mission which did not achieve a treaty, but did reestablish relations between her and the Portuguese. When the Dutch took over Luanda in 1641, Njinga immediately sent ambassadors to make an alliance with them. During these years, she moved her capital from Matamba to Kavanga, where she conducted operations against the Portuguese. Though Ndongo forces won a significant victory over the Portuguese in at the Battle of Kombi in 1647, nearly forcing them to abandon the country and laying siege to their inland capital of Masangano, a Portuguese relief force led by Salvador de Sá in 1648 drove out the Dutch and forced Njinga to return to Matamba. Although she maintained a symbolic capital at Kindonga, an island in the Kwanza River where she and her predecessor had ruled, the real capital was at the town of Matamba (Santa Maria de Matamba). Njinga had been baptized as Ana de Sousa while in Luanda in 1622, and in 1654 she began peace overtures to Portugal.

Njinga hoped that a peaceful relationship with Portugal would allow her to settle her kingdom and determine a successor, as she had no children. She formed a close alliance with a related family, whose leader João Guterres Ngola Kanini, became one of her most important councillors. She was also anxious to remove Imbangala forces, led by Njinga Mona, from her army and place them under her direct control. For this reason she also sought to reconcile with the Catholic Church. This strategy was successful, she signed a peace treaty in 1657 and Italian Capuchin missionaries began working in her lands. They regarded Njinga in her later days as a model Christian and thousands of Matamba subjects were baptized.