This volume is the proceedings of the 5th MSJ Seasonal Institute "Schubert Calculus" held at Osaka City University, September 17th–27th, 2012. It is recommended for all researchers and graduate students who are interested in Schubert calculus and its many connections and applications to related areas of mathematics, such as geometric representation theory, combinatorial aspects of algebraic varieties arising in Lie theory, and equivariant topology. Alain Lascoux, who is one of the pioneers of modern Schubert calculus, and a contributor of this volume, passed away during the time of editing process of the proceedings. The volume is dedicated to him.Published by Mathematical Society of Japan and distributed by World Scientific Publishing Co. for all markets except North America