Kaunda's father, who was from Nyasaland (now Malawi (Malaŵi)), was a schoolteacher; his mother, also a teacher, was the first African woman to teach in colonial Zambia. Both taught among the Bemba ethnic group in northern Zambia, where young Kaunda received his early education, completing secondary school in the early 1940s. Like the majority of Africans in colonial Zambia who achieved some measure of middle-class status, he also began to teach, first in colonial Zambia and in the middle 1940s in Tanganyika (now Tanzania).

Kaunda returned to Zambia in 1949. In that year he became interpreter and adviser on African affairs to Sir Stewart Gore-Browne, a liberal white settler and a member of the Northern Rhodesian Legislative Council. Kaunda acquired knowledge of the colonial government as well as political skills, both of which served him well when later that year he joined the African National Congress (ANC), the first major anticolonial organization in Northern Rhodesia. In the early 1950s Kaunda became the ANC's secretary-general, functioning as its chief organizing officer, a role that brought him into close contact with the movement's rank and file. Thus, when the leadership of the ANC clashed over strategy in 1958–59, Kaunda carried a major part of the ANC operating structure into a new organization, the Zambia African National Congress.

Kaunda became president of the new organization and skillfully used it to forge a militant policy against the British plan for a federation of the three central African colonies—Southern Rhodesia, Northern Rhodesia, and Nyasaland. African leaders opposed and feared any such federation because it would tend to place ultimate power in the hands of a white minority of settlers. Kaunda employed the Zambia congress as an instrument for executing what he called “positive nonviolent action,” a form of civil disobedience against the federation policy. His campaign had two major results: first, the British government modified the federation policy and eventually agreed to discard it; second, the imprisonment of Kaunda and other militant leaders elevated them to the status of national heroes in the eyes of the people. Thus, from 1960 on, the nationwide support of Zambia's independence movement was secured, as was too the dominant status of Kenneth Kaunda in that movement.

Kaunda was released from prison by the colonial government on Jan. 8, 1960. At the end of that month he was elected president of the United National Independence Party (UNIP), which had been formed in October 1959 by Mainza Chona, a militant nationalist who was disenchanted with the older ANC. The UNIP enjoyed a spectacular growth, claiming 300,000 members by June 1960. In December 1960 the British colonial authorities invited Kaunda and several other UNIP leaders to participate in discussions on the status of the three colonies at a conference in London. Early in the following year the British government announced that formal decolonization of Zambia would commence.

The first major elections leading to final decolonization were held in October 1962. The constitutional proposals upon which the election was based provided the European settlers in Northern Rhodesia with a disproportionate share of the votes. Yet the two major African parties—the UNIP and ANC—gained a majority of the votes. The UNIP was the winner, gaining 15 of the 37 seats in the new Legislative Council.

The UNIP's success was attributed overwhelmingly to the leadership of Kaunda. He had been astute both in allaying the European settlers' fears that an African regime would unfairly disregard their interests and in quelling the factionalism prevalent in large sections of the country's African population. It was this same skill that enabled Kaunda to negotiate further constitutional advances, and in 1964 Zambia was granted independence with Kaunda as its president.

Like other African leaders, Kaunda faced many complex postindependence problems, especially the issue of tribalism. He succeeded in continuing to negotiate on this issue, saving Zambia the trauma of tribal civil war. Nevertheless, interparty political violence occurred during the elections of 1968, in which Kaunda and his party were returned to power. In response, Kaunda in 1972 imposed one-party rule on Zambia, and in 1973 he introduced a new constitution that ensured his party's uncontested rule.

In the 1970s Kaunda's government acquired a majority interest in the country's copper-mining operations and undertook to manage other industries as well. While investing large sums in the mining sector, the government neglected agriculture while nevertheless having to spend increasing sums on subsidized food for the urban poor. These policies reduced agricultural production and increased Zambia's dependence on exports of copper and on foreign loans and aid. From the 1970s on, the result of these policies was the progressive impoverishment of Zambia; unemployment rose, living standards steadily declined, and the provision of education and other social services decayed. In foreign affairs, Kaunda led other countries of southern Africa in confronting the white-minority governments of Rhodesia (now Zimbabwe) and South Africa. He imposed economic sanctions against Rhodesia in the 1970s at great cost to his country's own economy, and in the late 1970s he allowed Zambia to be used as a base by black nationalist guerrillas led by Joshua Nkomo (Nkomo, Joshua).

In 1976 Kaunda assumed emergency powers, and he was reelected as president in one-candidate elections in 1978 and 1983. Several attempted coups against him in the early 1980s were squelched. The Zambian economy continued to deteriorate owing to a fall in the world price of copper (Zambia's chief export), the rising price of oil (its chief import), the withdrawal of foreign aid and investment by developed countries, and worsening corruption within Kaunda's government. With public dissatisfaction mounting and a credible political opposition in the process of formation, Kaunda in 1990 legalized opposition parties and set the stage for free, multiparty elections in 1991. In the elections, held late that year, Kaunda and the UNIP were defeated by the Movement for Multiparty Democracy (MMD) in a landslide. Kaunda's successor, Frederick Chiluba, took office on Nov. 2, 1991.

After leaving office, Kaunda clashed frequently with Chiluba's government and the MMD. He planned to run against Chiluba in the 1996 presidential election but was barred from doing so after constitutional amendments were passed that made him ineligible. On Dec. 25, 1997, Kaunda was arrested on charges of inciting an attempted coup that had occurred earlier that year in October. He was released six days later, but he was placed under house arrest until all charges were withdrawn in June 1998. The next month, Kaunda announced that he would resign from his role as UNIP's president once a successor was chosen. However, the lack of agreement regarding his successor caused a rift within the UNIP, and ultimately Kaunda did not resign until 2000. In March 1999 a judge ruled that Kaunda should be stripped of his Zambian citizenship because his parents were from Malawi and furthermore, because of that fact, Kaunda had held office illegally for most of his period in government. Kaunda mounted a challenge, and his citizenship was restored the next year when the petition that generated the court ruling was withdrawn.

In 2002 Kaunda was appointed the Balfour African President-in-Residence at Boston University in the United States, a position he held until 2004. In 2003 he was awarded the Grand Order of the Eagle in Zambia by Chiluba's successor, Pres. Levy Mwanawasa.