This book constitutes the refereed proceedings of the 14th International Conference on Logic Programming and Nonmonotonic Reasoning, LPNMR 2017, held in Espoo, Finland, in July 2017. The 16 full papers and 11 short papers presented in this volume were carefully reviewed and selected from 47 submissions. The book also contains 4 invited talks. The papers were organized in topical sections named: nonmonotonic reasoning; answer set programming; LPNMR systems; and LPNMR applications.