Mr Aristide's victory was virtually guaranteed as most of the opposition boycotted the election.
The Electoral Council in Haiti announced that he had won with almost 92% of the vote.
Mr Aristide's victory was virtually guaranteed as most of the opposition boycotted the election.
There are no figures for the final turnout in the election, but preliminary figures released by the electoral authority suggested about 60% of voters turned out.
The opposition disputes this, saying that fewer than 5% of voters took part.
The United States and the Organization of American States have expressed reservations about the election, saying that deficiencies from parliamentary voting earlier this year should have been addressed first.
Atmosphere of violence
Haiti has 4.8 million registered voters, but an alliance of 15 opposition parties boycotted the vote.
The build-up to the elections was marred by violence including at least 10 bomb explosions.
A 14-year-old boy was killed and 14 others injured in a series of bomb attacks that rocked the capital, Port-au-Prince.
Dozens of people were killed or wounded in previous weeks.
The opposition protested the disputed results of May's legislative elections which, according to international observers, were miscalculated in favour of Mr Aristide's party.
Three of seven presidential candidates withdrew from the race to protest at pre-election violence.
They also accused Haiti's electoral council of favouring Mr Aristide's ruling party.
Second time round
Mr Aristide, a former Roman Catholic priest, was president of Haiti from 1991 to 1996.
He was elected president the first time with a huge majority, similar to Wednesday's result.
His rule came to an abrupt end just seven months later when a military coup forced him from power.
A US-led invasion restored him to power three years later until 1996 when Rene Preval assumed presidency.