Chief Justice Mogoeng Mogoeng has described Justice Edwin Cameron as "brave and bold", saying that when HIV had a stigma, he stood up and declared openly that his status was positive.
"He knew the attitude of South Africans at the time because nobody had stepped out and prepared them that this is a condition like any other that requires medical attention," he said.
Cameron contracted the virus in the late 1980s and revealed that he was HIV-positive in 1999.
Mogoeng said Cameron could afford antiretrovirals and therefore could have chosen to "mind his own business and care less about others. But not Edwin Cameron. He is not that type," he said.
Mogoeng added that Cameron was the kind of man who deserved to be recognised by the country for the role he played.
"We have enjoyed this man... " Mogoeng said.
He said Cameron was not only a selfless person but also a humble one.
Cameron retired as a judge on Tuesday - the 25th anniversary of his appointment as a judge.
Cameron, a keen cyclist, was appointed to the Constitutional Court in 2008 by then-acting president Kgalema Motlanthe.
Among those who attended the ceremony were speaker of Parliament Thandi Modise, Minister of Justice and Correctional Services Ronald Lamola, former deputy chief justice Dikgang Moseneke and president of the Supreme Court of Appeal, Judge Mandisa Maya, among others.
Cameron worked as a human rights lawyer during apartheid, defended ANC members and fought for gay and lesbian equality, according to his profile on the Constitutional Court's website.