This book constitutes thoroughly refereed and revised selected papers from the 7th International Symposium on Combinatorial Optimization, ISCO 2022, which was held online during May 18-20, 2022. The 24 full papers included in this book were carefully reviewed and selected from 50 submissions. They were organized in topical sections as follows: Polyhedra and algorithms; polyhedra and combinatorics; non-linear optimization; game theory; graphs and trees; cutting and packing; applications; and approximation algorithms.