The gulf country, which has a history of gender segregation, was elected into the commission that aims to promote women's rights.
Saudi Arabia was last week elected to the UN Commission on the Status of Women, drawing backlash from human rights watchdogs.
The criticism has centred around the inclusion of the gulf country into the 45 member body that is "exclusively dedicated to the promotion of gender equality and the empowerment of women," despite its history of gender segregation.
"Electing Saudi Arabia to protect women's rights is like making an arsonist into the town fire chief," said UN Watch's executive director, Hillel Neuer. "It's absurd."
"Every Saudi woman," said Neuer, "must have a male guardian who makes all critical decisions on her behalf, controlling a woman's life from her birth until death."
Social media users also took to Twitter to express their sentiments about the appointment.
Saudi Arabia is on the UN's women's rights commission.— Rijul Ballal (@RijulBallal) April 24, 2017
Punchline not included.
In Saudi Arabia, women are legally subject to a male guardian, who must give his approval for basic decisions on education, marriage, travel and even medical treatment.
Saudi authorities have over the last decade granted new opportunities for women to study and work. But women are still barred from driving and must obey a strict dress code requiring that they wear loose robes when in public.