The document shows that the world still faces a learning crisis and a skills crisis that is leaving girls ill-prepared to develop critical knowledge to participate in the Fourth Industrial Revolution. This risks reversing gains in women's participation in the workforce. This report seeks to call attention to the potential of STEM education to transform gender norms in the education system, to improve quality learning opportunities for girls, and to highlight key actions that can accelerate girls' transition between education and technical expert jobs in STEM industries. Critically, STEM education also has the potential to contribute to personal empowerment, transformation of communities and nations, and building economies for the future. The evidence presented here provides a foundation for a call to action for global, national and regional actors. The following questions are addressed: (1) How is the learning crisis affecting girls? (2) Why is STEM learning so important for girls? (3) What are the gender disparities in STEM education? (4) Why are girls under-represented in STEM? and (5) How can we transform opportunities for girls through gender-responsive STEM education? The document concludes with a call to action. [Research input for this report was provided by Carolina Belalcazar. EQUALS Global Partnership for Gender Equality in the Digital Age (launched by ITU and four founding partners) assisted in the preparation of this report. For the summary of this report, see ED627517.]