They said Saturday's vote in the ultra-conservative Islamic kingdom is a step towards improving the rights of the Gulf nation's roughly 10 million females.
But it will not directly help end a ban on women driving -- the only prohibition of its kind in the world -- or the "guardianship" system, they said.
Male guardians are family members who must authorise a woman's travel, work or marriage.
Saudi Arabia has some of the world's tightest restrictions on women, who must cover themselves in black from head to toe when they appear in public.
Restaurants and other public facilities are segregated, a division reflected in the voting, when men and women cast ballots at separate facilities.
Iman Fallata, a founder of the Baladi Initiative, which helped prepare women for the vote, told AFP that although ending the guardianship system is a priority, "we (will) not put a strong hope for this" immediately.
"We know it's still early stages. We know that the way is long... but we are on the right way," she told AFP on the sidelines of a ceremony at which the Baladi Initiative was named a winner of this year's Chaillot Prize.
The annual award from the European Union delegation in Riyadh honours those working for human rights in the Gulf.
Fallata said Baladi's immediate goal is to push for 50 percent female representation on the council seats, which will be appointed by the ministry of municipal affairs.
The 2,106 council seats up for election last Saturday account for two-thirds of total seats, with the rest appointed.
Twenty women had been elected throughout the kingdom, the election commission spokesman said on Monday.
That is fewer than one percent of the total.
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STEP BY STEP
Their victory "doesn't have anything to do with" ending the driving ban or guardianship, said Laila al-Kadhem, another Baladi founder.
But she told AFP that any progress for Saudi women "will push to other developments in other areas" indirectly.
Baladi, founded in 2010, pushed for women's electoral participation and will support the new councillors with training and whatever support they need, Kadhem said.
She told the EU ceremony that the total number of elected women was "maybe below our expectations", but the fact that there were 979 candidates was heartening.
"I think it's an enormous success," she said.
Referring to the increased room for activists in the kingdom, another Chaillot Prize winner, Jafar al-Shayeb, told the ceremony that 15 years ago people "never thought that women would one day participate in elections".
The late king Abdullah introduced municipal elections for men in 2005 and said women would participate this time around.
In 2013, he named women to the appointed Shura Council, which advises the cabinet.
Columnist Abdulateef al-Mulhim, writing in Monday's Arab News, suggested the polls are just the start of an expanded place for women in the kingdom, under Abdullah's successor King Salman.
"These polls reminded us of the day when the first batch of women got enrolled in the education system. With the passage of time, the ratio of women enrolled in universities is equal if not more than men," he wrote.
Eman al-Nafjan, a blogger and activist, told AFP by telephone that while the election results were "fantastic", they are unrelated to the push for the right to drive and an end to guardianship.
But, she said, "every opportunity where women are allowed a bit of freedom, they take advantage of it".
Amal Badreldin al-Sawari, who was a losing candidate in the election, said that although the number of winning women is small, they have laid a path for women's rights.
"It is good to start step by step," she said.