The 89-year-old politician, who has led the southern African nation since 1980, received more than 2.1 million of the 3.4 million votes cast Wednesday, the Mail & Guardian reported. The term is for five years.
Mugabe, of the Zanu-PF, easily out-distanced rival Morgan Tsvangirai of the Movement for Democratic Change, who garnered under 1.2 million votes, the South African weekly said.
The results were announced in Harare Saturday evening by Zimbabwean Electoral Commission Rita Makarau.
"Like the chairperson [Makarau] said it was peaceful, free, fair, transparent countrywide," Zanu-PF politburo member and Defense Minister Emmerson Mnangagwa said. "And I'm very, very, very happy that I represent the winner President R.G. Mugabe."
Mnangagwa, who signed off on the results as Mugabe's agent, advised the MDC-T to back away from party Treasurer Roy Bennett's earlier call for the people of Zimbabwe to not cooperate with the ruling party.
"They have that democratic right to do wrong things. They should have listened to the advice given by the chair of SADC [Southern Africa Development Community] observer mission that they should respect the results. But the route they're taking is that their political career is buried and buried for good."
Tsvangirai's election agent, Obert Gutu, said he refused to sign the election certification form because he "will not legitimize the monumental fraud.:
"The refusal symbolizes the MDC's total rejection and total contempt of the farce," Gutu said.
Earlier, Bennett said the Zanu-PF party should "rule by themselves" and called for "passive resistance" after the Zanu-PF won 137 of 210 seats in the national Legislature.
"I'm calling on the people of Zimbabwe, who are our constituents and who we represent in the positions we hold, for passive resistance and for total disengagement," he said. "And let Zanu-PF rule and rule by themselves and bring the country to a standstill."
The Zimbabwe Election Support Network, a local monitoring group, said the election had been "seriously compromised" because as many as 1 million people had been unable to vote.
The election was fair and free "from the campaigning point of view," said former Nigerian President Olusegun Obasanjo, head of the African Union mission.
South Africa has challenged critics to provide evidence of election fraud, while the SADC described the election as "free and peaceful."