Gender equality is a fundamental human right and a powerful driver for accelerating economic growth by unlocking the potential of women and men not only in Kenya but also at international level. Gender wage gap is a manifestation of gender wage discrimination against women or men at workplace. This discrimination is mostly demonstrated where qualified women are offered lower pay as compared to their men counterparts at the same level of work. The same situation is experienced at glass ceiling with larger gender wage gaps at the upper levels. Therefore, once the government has put in place its development policy framework, it is imperative to ensure execution of gender equality in order to address the problems of gender wage gap. However, despite great awareness and existence of gender equity in the policy documents and blue prints for National development agenda, particularly of the Kenya Vision 2030, the Big four agenda and the Global agenda on Sustainable Development Goal 5 on achieving gender equality and empowerment of all women and girls and legal provisions in Kenya Employment Act 2007, gender wage gap has remained high at the work place in Kenya. Drawing on secondary data, this paper examines the root causes of gender wage gap and investigate gender wage gap and its implications on shared prosperity for sustainable development by exploring what can inform institutional policy decisions in order to narrow the wage differentials. The article argues that reducing gender wage gap has great positive implications on shared prosperity including access to new economic opportunities, opening spaces for decision-making and expanding human capital in education sector. To effectively achieve this reduction, enforcement mechanism is necessary by government and institutional managers on effective implementation of policy on gender equality if narrowing the gender wage gap is going to be achieved for sustainable development in Kenya.