His 40-year leadership of the former British colony was marked with bloodshed, persecution of political opponents and vote-rigging on a large scale.
Born in then Rhodesia, Mr Mugabe co-founded the Zimbabwe African National Union (ZANU) in 1963, a resistance movement against British colonial rule.
He was jailed for anti-government comments between 1964 and 1974.
He became prime minister in 1980 of the new Republic of Zimbabwe and assumed the role of president seven years later.
In 2000 he led a campaign to evict white farmers from their land, which was given to black Zimbabweans, and led to famine.
Mugabe retained a strong grip on power, through controversial elections, until he was forced to resign in November 2017, at age 93.
Mugabe's successor, close ally Emmerson Mnangagwa, tweeted: "It is with the utmost sadness that I announce the passing on of Zimbabwe's founding father and former President, Cde (Comrade) Robert Mugabe.
"Cde Mugabe was an icon of liberation, a pan-Africanist who dedicated his life to the emancipation and empowerment of his people. His contribution to the history of our nation and continent will never be forgotten. May his soul rest in eternal peace."