Shena Simon (1883-1972), a leading English socialist and educationist, actively called for the reform of secondary education in the 1930s and 1940s in order to bring the ideal of 'equality of opportunity' into the English educational system. This paper explores the continuity and changes in Simon's proposed reforms in relation to her ideals of social democracy from the appearance of the Spens Report (1938) to the publication of her book, "Three Schools or One?" (1948). In addition, Simon's transnational visits to the Soviet Union, the USA and Scotland, as well as the impact of her international and comparative perspectives on different educational systems on her policy agenda, are also examined. It concludes that as many policy issues shown in the current paper continue to be debated, Simon's democratic ideals and discourses are still relevant in the present and suggest implications for the future of secondary education in England.