This book constitutes the refereed proceedings of the 4th International Workshop on Systems and Frameworks for Computational Morphology, SFCM 2015, held in Stuttgart, Germany, in September 2015. The 5 revised full papers and 5 short papers presented were carefully reviewed and selected from 16 submissions. The SFCM Workshops focus on linguistically motivated morphological analysis and generation, computational frameworks for implementing such systems, and linguistic frameworks suitable for computational implementation. SFCM 2015 and the papers presented in this volume aim at broadening the scope to include research on very underresourced languages, interactions between computational morphology and formal, quantitative, and descriptive morphology, as well as applications of computational morphology in the Digital Humanities.