Mbuli collapsed while watching a match between the Cheetahs and the Reds at the Free State Stadium on Saturday night, the SABC reported.
He was treated at the scene before being rushed to the Mediclinic hospital in the city.
He was 46.
A family spokesperson told the broadcaster that the cause of death had not yet been determined.
The spokesperson requested that the family's privacy be respected as they tried to come to terms with the tragedy.
African National Congress spokesperson Jackson Mthembu described Mbuli as "an outspoken linguist who took pride in celebrating the diversity of South Africa and its people".
Mthembu said: "For decades, Vuyo Mbuli has been a constant presence in South African homes, tackling various issues of national importance with wit, charm, respect and an all-embracing and inclusive manner.
"It was this ability to converse with and entertain all types of people that also made Mr Mbuli a sought after public speaker and master of ceremonies, jobs he would carry out with flair."
The ANC also praised Mbuli's tireless efforts in promoting dialogue on various issues of relevance to South Africa's national discourse.
As such, his death was a loss to the broadcasting community, particularly the SABC.
"As we remember him, it is one of his favourite phrases that today rings true—'mintiro ya bula bula'—your work speaks for you."
The party extended its condolences to Mbuli's family, friends and colleagues.
"In this, the last time, his signature sign off—'Sharp Sharp'—came too soon and he will be sadly missed," Mthembu said.
Earlier, the Young Communist League of SA expressed its shock and sadness, saying it would "miss his friendliness, fairness and being a very professional presenter".
"We send our deepest condolences to his family, his colleagues at the SABC, and all the viewers of Morning Live," said spokesperson Khaya Xaba. - Sapa.