The president, who has ruled for 20 years, retained power after winning 83.5% of the vote and could now see EU sanctions lifted for four months.
Alexander Lukashenko has won a fifth term as president of Belarus with a landslide victory that could see an easing of relations with the west and raise questions about his ties to Vladimir Putin's Russia.
Lukashenko's re-election five years ago led to mass protests and the imprisonment of leading opposition figures, but support for his 20-year-old regime has risen since he cast himself as a guarantor of stability in the face of economic crisis and a pro-Russia separatist conflict in neighbouring Ukraine.
Lukashenko won 83.5% of the vote, the central election commission said laste on Sunday, slightly more than the 80% he won in the 2010 elections. Turnout was 86.75%, the commission added.
The west has long ostracised Lukashenko's Belarus – described in 2005 by then US secretary of state Condoleezza Rice as “Europe's last dictatorship" – over its human rights record and clampdown on political dissent. It has imposed economic sanctions on some Belarusian officials and companies.
Nevertheless, Lukashenko's criticism of Russia's annexation of the Crimea peninsula in Ukraine last year, his hosting of Ukraine peace talks and his pardoning of six opposition leaders in August suggest he is seeking to improve his image in the west, observers say.
“We have carried out everything the west wanted on the eve of the elections. If there is a desire in the west to improve our relations, nobody and nothing can prevent that," Lukashenko said as he cast his vote. “The ball is now firmly in the west's court."
Relations with Moscow, meanwhile, have shown signs of strain. In September, Vladimir Putin approved a plan to build an airbase in Belarus, but early this month Lukashenko said his country had no need for such a base, appearing to bow to public protests on the eve of the election.
The EU will lift its sanctions on Belarus, including those on Lukashenko, for four months after Sunday's vote, barring any last-minute crackdown, diplomatic sources said on Friday.
Previous elections in Belarus wereconsidered unfair by western observers and the Organisation for Security and Cooperation in Europe (OSCE), which is monitoring Sunday's vote, said in September the ballot represented a “pivotal moment" for Belarus to demonstrate a willingness to hold free and fair elections.
The election turnout was boosted by authorities organising a huge early vote that began on Tuesday, including for soldiers and students. Over a third of the electorate of more than seven million voted ahead of Sunday's polls.
Turnout was highest in the northern Vitebsk region where 91% of voters cast their ballots, and topped 90% in two other regions. It was lowest in the capital, Minsk, at 73.33%, the commission said on its website.
The OSCE will present a report on their election monitoring on Monday, after which Brussels will release a formal statement, an EU spokesman said.