This is a 26-slide presentation made by Dr. Katherine Dix at the Alliance of Girls Schools Australasia Educators’ Fearless Girls Strong Women Conference 2018. Data from research studies such as the Progress in International Reading Literacy Study (PIRLS), the Programme for International Student Assessment (PISA), Trends in Mathematics and Science Study (TIMSS), and NAPLAN have been utilised to compare girls’ and boys’ academic achievement in single-sex and co-educational schools. The data sets, which inform policy monitoring by identifying key performance measures and evaluating progress towards educational goals for Australian students by international standards, are examined to identify any gender biases in Australian and international trends in reading and mathematics for Years 3-4 to Year 9 students. The effects of socio-economic status, year level and school type are taken into consideration, learning gaps are identified, and a range of teaching strategies are suggested as possible solutions to developing more evenly balanced outcomes in academic achievement for both genders.