Most opposition parties boycotted the results announcement in the capital Windhoek on Tuesday evening, Namibian newspapers reported.
Windhoek was reported to be calm on Wednesday, with no celebrations or protests and people carrying on with their normal lives.
“The Namibian nation has chosen peace and stability,” Nandi Ndaitwah said after announcing the victory.
Swapo has been in power in the large but sparsely populated southern African country since independence in 1990.
Party stalwart Nandi-Ndaitwah, who currently serves as vice president, is a trusted leader who has held senior government positions for 25 years.
South African President Cyril Ramaphosa congratulated Nandi-Ndaitwah on Wednesday at X.
“Being elected as the fifth President of the Republic and the first woman to hold such a high office in our region is a testament to democracy and its ability to transform our societies,” he said in a statement.
Once sworn in, she will join an exclusive club as Tanzania’s Samia Suluhu Hassan is currently Africa’s only female president.
In the parliamentary elections held around the same time, Swapo won 51 of the 96 seats elected, losing 12, and barely maintaining a majority. The IPC won 20 seats and will become the official opposition party.
Windhoek-based political journalist Tirivangani Masawi told the BBC’s Newsday program that the election was Swapo’s “worst performance since independence.”
Itula, a trained dentist, is seen as more charismatic than Nandi-Ndaitwah and undermined Swapo’s popularity in the last presidential election in 2019, reducing voter turnout to 56% from 87% five years ago.
“We will seek justice through the courts,” the IPC said, encouraging people who felt they were unable to vote due to mismanagement by the Electoral Commission to go to the police and make statements.
The IPC’s Claus Goldbeck said the BBC vote was “organized chaos”.
There were not enough ballots and the scanners at many polling places were broken, so some people had to go home after standing in line for 14 hours.
“It took the Electoral Commission of Namibia (ECN) four years to resolve the issue,” he said.
The ECN acknowledged failures in organizing the vote and a shortage of ballot papers. But chairman Elsie Nghikembua denied the fraud allegations.
“I urge all Namibians to accept the results in a spirit of unity, diversity, understanding and reconciliation,” she said.
Swapo led the fight for nationality against apartheid in South Africa. There was some speculation ahead of last Wednesday’s general election that it would suffer the fate of other liberation parties in the region.
South Africa’s African National Congress (ANC) lost all of its parliamentary seats in May, and Botswana’s Democratic Party was ousted from power for the first time in almost 60 years after elections in October.
