Saudi Arabia, the birthplace of Islam, follows the austere Wahhabi school of Sunni Islam. Women cannot drive, must be covered up in public and should not mix with men outside their immediate family.
Nadia Bakhurji said she had been elected among 71 candidates for the 10-person board of the Saudi Engineers Council in a vote which took place earlier this week. The results were reported in Saudi papers on Wednesday.
"Saudi ladies are now beginning to have faith that they can actually achieve important milestones in their career," the Saudi- and British-educated architect told Reuters.
"It is wonderful that King Abdullah is giving positive indicators. He is definitely supporting women."
Saudi women were barred from voting or standing in municipal elections earlier this year. But King Abdullah, who ascended the throne in August, has made the promotion of women in society a priority for the country's economic development.
Two women triumphed last month in an unprecedented election to the Chamber of Commerce in the city of Jeddah, the country's first vote where women campaigned openly for office.
Mindful of opposition from the kingdom's powerful religious establishment, the king has said any steps will be in line with Islamic principles. The vote by around 1,500 engineers to the national body, which also groups architects and designers, would also boost efforts to strengthen civil society in Saudi Arabia, where many professionals lack independent representation, Bakhurji said.