Dressed in traditional attire -- with men wearing a white tunic called a "kanzu' and women donning "bitenge" dresses -- the revellers prayed for the 68-year-old monarch, whose ancestors ruled a region that includes Uganda's modern-day capital Kampala.
As the sound of royal drums reverberated, the king, wearing the customary ceremonial attire of a leopard skin and cloth made from tree bark, waved to the crowd while a supporter hoisted him onto his shoulders.
"This is a joyous moment", said Charles Peter Mayiga, prime minister of Buganda, which is a constitutional monarchy within Uganda.
"We are here to celebrate the coronation but also to pray for the good health of our king and (that) he continues to lead his kingdom," said shop attendant Annet Nakafeero, 34, who brought her four-year-old daughter to the festivities.
Schoolchildren performed songs during the celebration at the hilltop palace in Kampala, as officials from the kingdom and the central government watched.
The king, known as the Kabaka, occupies a largely ceremonial role, but has previously had run-ins with the government of President Yoweri Museveni, who has ruled over Uganda with an iron fist.
In 2009, the authorities closed down the Buganda-run radio station CBS for a year, accusing its broadcasters of "inciting hatred" after people loyal to the monarch began rioting in Kampala over the government's decision to restrict his movements within the kingdom.
At least 27 people died during the anti-riot operations conducted by the security services.
The bush war that brought Museveni to power in 1986 was successful largely due to Buganda's support.
Many in Buganda despised Museveni's rival, former president Milton Obote, because he outlawed tribal kingdoms and forced the Kabaka into exile.
