High Court Chief Justice Maruping Dibotelo said in a statement that Khama "has been re-elected as the President of the Republic after his political party, the Botswana Democratic Party (BDP) garnered at least 29 of the 57 parliamentary seats" at Friday's general election.
Khama will be inaugurated on Monday, said Dibotelo in a statement broadcast on national radio and television.
The newly formed Umbrella for Democratic Change (UDC), led by Duma Boko, which was contesting elections for the first time becomes the official opposition with 12 seats in parliament.
Khama, 61, is the son of the country's first president, Seretse Khama. He is also a traditional chief of the Bangwato clan and benefited from his strong rural support.
But he faced a challenge in urban areas, where opposition parties have made inroads since the formation in 2010 of a breakaway party, the Botswana Movement for Democracy (BMD), which is now part of the UDC coalition.
No celebrations took place in the streets of Gaborone after the announcement of the results in the early hours of Sunday morning.
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