Rights groups warn the country of 170 million is heading for virtual one-party rule, after the boycott by the main opposition Bangladesh Nationalist Party (BNP), though Western nations, key clients of its garments industry, have urged free elections.
On walls in Dhaka, the capital, slogans painted in red and blue exhorted voters to pick "Once again, Sheikh Hasina" and "Vote for the boat", the symbol of her Awami League party, before campaigning wraps up on Friday.
With the ballot outcome all but assured, however, some voters see little reason to turn out.
"My whole family are hardcore Awami League supporters," said school teacher Shayed Uz Zaman, adding that they planned to make use of Sunday's voting day holiday to visit their village in Kushtia, a district about 200 km (125 miles) from Dhaka.
"But there's no charm in voting this time. I know she is staying in power."
Sunday is usually a working day in mainly Muslim Bangladesh.
Another Awami League supporter, Minoti Rosario, who runs a grocery shop, said she felt her vote barely mattered as the "ruling party is winning anyway".
Votes in the South Asian nation's 12th general election since gaining independence from Pakistan in 1971 are expected to be counted on Sunday evening, with results due early on Monday.
About 120 million registered voters will choose 300 members of parliament in the vote, one of the world's largest such exercises this year. Women make up almost half of voters, while those casting a ballot for the first time number 15 million.
The BNP is not contesting because Hasina refused to accept its demand to cede power to a caretaker government to run the poll.
Troops have fanned out across Bangladesh to guard the polls, in addition to nearly 750,000 police officers, paramilitary and police auxiliaries. Police stepped up arrests of BNP leaders and workers after deadly protests in late October.
The risk of political violence was high, despite low expectations for voter turnout, said the International Crisis Group, an independent think tank.
"The election will not resolve Bangladesh's political crisis," said Pierre Prakash, its Asia director. "Since the 2008 election that brought the Awami League to power, the country has not held a credible national election."
In her last 15 years in power, Hasina, 76, has been credited with turning around the economy and the garments industry.
But critics have also accused her of authoritarianism, human rights violations, crackdowns on free speech and suppression of dissent, with some of them being jailed.
Her main rival and two-time premier, BNP leader Khaleda Zia, is effectively under house arrest on graft charges the opposition says have been trumped up.
Khaleda's son, Tarique Rahman, is the acting chairman of the party, but he is in exile after several charges brought against him that he denies.
The economy has also slowed sharply since the Russia-Ukraine war boosted prices of fuel and food imports, forcing Bangladesh to turn to the International Monetary Fund for a bailout of $4.7 billion last year.
