In an annual speech before his advisory assembly, or Shura Council, the Saudi monarch said he ordered the step after consulting with the nation's top religious clerics, whose advice carries great weight in the kingdom.
"We refuse to marginalize the role of women in Saudi society and in every aspect, within the rules of Sharia," Abdullah said, referring to the Islamic law that governs many aspects of life in the kingdom.
The right to vote is by far the biggest change introduced by Abdullah, considered a reformer, since he became the country's de facto ruler in 1995 during the illness of King Fahd. Abdullah formally ascended to the throne upon Fahd's death in August 2005.
This move seems very clearly related to the protests that Saudi women have been making about the government's continued unwillingness to let them drive.
Seizing on the season of protest in the Arab world, Saudi women's groups have also staged public defiance of the kingdom's ban on female driving. Saudi authorities went relatively easy on the women, who took to the roads earlier this year and gained worldwide attention through social media.
Abdullah said the changes announced Sunday would also allow women to be appointed to the Shura Council, the advisory body selected by the king that is currently all-male.
The council, established in 1993, offers opinions on general policies in the kingdom and debates economic and social development plans and agreements signed between the kingdom and other nations.
Saudi Arabia, the birthplace of Islam, follows deeply conservative social traditions and adheres closely to a strict version of Islam. Despite Abdullah's attempts to push through some social reforms, women still cannot drive and the sexes are segregated in public.