The gorilla — known as Rafiki, which means “friend” in Swahili — was part of the famed Nkuringo gorilla group that lives in the Bwindi Impenetrable National Park and is hugely popular with tourists.
Rafiki was reported missing on June 1 and his mutilated body was found the next day inside the park.
A postmortem report revealed that Rafiki was injured by a sharp device to his abdomen and internal organs.
Byamukama Felix was arrested a few days later with bush pig meat and several hunting devices in his possession, authorities said.
Byamukama pleaded guilty to several charges, including killing a gorilla, entering a protected area and being in possession of illegal meat.
He told authorities he killed Rafiki in self-defense when he went with a group to hunt in the park and they came across the group of gorillas. The silverback charged and he speared it, he said.
Three other men who were arrested with Felix remain in custody awaiting trial as they have pleaded not guilty.
Sam Mwandha, executive director of the Uganda Wildlife Authority, welcomed the court’s decision, saying, “Rafiki has received justice.”
“We are relieved that Rafiki has received justice and this should serve as an example to other people who kill wildlife.
“If one person kills wildlife, we all lose, therefore we request every person to support our efforts of conserving wildlife for the present and future generations,” he added.
At the time Rafiki died, the Nkuringo group had 17 gorillas, according to the Uganda Wildlife Authority.
The silverback was the dominant male in the group that also included three blackbacks or younger mature males, eight adult females, two juveniles and three infants.
The group was the first to reside in the southern section of the park that is home to about half of the world’s mountain gorilla population.