Young Namibians turned up in their thousands to queue at municipal offices, to submit written applications for land in urban areas.
The mass action was peaceful with no incidents reported.
Following the call of youth activist Job Amupanda, young Namibians formed long queues in most towns and at the coastal town of Swakopmund, over 3,000 applications were handed in by 10am.
"We received preliminary figures from five towns so far showing that over 25,000 youths submitted applications, we are waiting for more figures which we will make public on Sunday," Amupanda said late on Friday.
"The youth of this country have redefined Namibia," he added.
The mass applications appear to be the biggest peaceful mass action since Namibia's independence in 1990.
The Affirmative Repositioning activists had used social media to organise the mass action and to distribute template application forms.
Many youths across the country posted updates and photos on social media throughout the day about the long queues and their participation in the action.
Police chief, Inspector General Sebastian Ndeitunga, said they would "not hesitate to take action" should the mass application exercise become unruly.
Swapo leaders criticised the mass action and urged members not to participate.
On Monday, Swapo secretary general Nangolo Mbumba called it "an ongoing campaign to instigate landless people against government structures and eventually against the Swapo party.
"The position of the Swapo party on this issue is that these efforts to disrupt peace and stability in our country must be rejected," Mbumba said in a statement.
Amupanda was the information secretary of the Swapo Youth League, but was suspended late last year after he illegally occupied an empty and unserviced plot in an upmarket Windhoek suburb for two days.
Due to soaring prices for houses and flats, and high rentals, particularly in Windhoek, developers buy large tracts of land to build tiny but expensive townhouses.
High living costs are increasingly frustrating ordinary Namibians who cannot afford even modest accommodation.