Although Sustainable Development Goal (SDG) 5, Gender Equality, references many international law provisions and principles on gender equality and empowerment of women and girls, nevertheless, like their precursor, the 2000 Millennium Development Goals, the SDGs do not integrate gender as a cross-cutting issue across all the SDGs. The adoption of the gender mainstreaming approach endorsed by the 1995 Beijing Declaration and Platform for Action during the fourth World Conference on Women in Beijing in September 1995 compromises the implementation of SDG 5. This chapter argues that by adopting a formalist approach to equality, SDG 5 does not fully recognize the differences among women – differences of class, race, disabilities, ethnicities, nationalities, religion, and those brought about by colonialism – and thus falls victim to the classical criticism of international law’s genderedness and essentialism.