Tshisekedi officially triumphed with 73.47 percent and the vote passed largely peacefully in a country long torn by violence and instability.
The opposition branded the ballot a sham.
Voting was officially extended by a day due to logistical snarls and polls were open for days after in remote areas.
Parties supporting Tshisekedi garnered more than 90 percent of the seats in parliament, allowing him to legislate with ease.
The new prime minister will be tasked with pushing the president’s declared priorities of employment, youth, women and national cohesion for the nation of about 100 million people.
He first became president in 2019 promising to improve living conditions in the DR Congo — which boasts mineral riches but has a largely impoverished population — and put an end to 25 years of bloodshed in the east.
Tshisekedi failed to keep those promises but campaigned for a second term on his achievements such as free primary medication, asking for another mandate to “consolidate” the progress.
According to the United Nations, some seven million people have been internally displaced by conflict in the DR Congo, one of the world’s poorest countries.
The security situation has worsened in North Kivu province where a Rwanda-backed rebel group M23 has seized swathes of territory over the last two years.
AFP