The election, which lacked major opposition candidates and which has degenerated into violent protests, has received its final results from the country's electoral commission.
"I declare Samia Suluhu Hassan elected president of the United Republic of Tanzania through the CCM party," said Electoral Commission Chairman Jacobs Mwambegele on state television.
Now awaits a short ceremony where she will once again be sworn in as president.
Wednesday's election day derailed into chaos and violence, which has continued since. Crowds are furious at the fact that the president's main challengers have been either imprisoned or banned from participating, as well as at increased repression of government critics in general.
According to the opposition, 700 people have been killed in the violence.
The internet and many other communications have been shut down and it is difficult to follow what is happening. The Swedish Ministry of Foreign Affairs has been advising against non-essential travel to Tanzania since Friday due to the security situation in the country.
