This volume LNCS constitutes the refereed proceedings of 31st European MPI Users' Group Meeting, EuroMPI 2024, held in Perth, WA, Australia, during September 25-27, 2024.The 8 full papers presented here were carefully reviewed and selected from 19 submissions. Improvements for MPI and MPI Ecosystem.

Compile time Correctness Checks and Optimization.- SPMD IR Unifying SPMD and Multi Value IR Showcased for Static Verification of Collectives.- Annotation of Compiler Attributes for MPI Functions.- Limitations and Extensions for GPGPUs in MPI.- Understanding GPU Triggering APIs for MPI X Communication.- Stream Support in MPI without the Churn.- Improvements for MPI.- Improved MPI Collectives for 3D FFT.- To Share or Not to Share A Case for MPI in Shared Memory.- MPI Ecosystem.- Dynamic Resource Management for In Situ Techniques using MPI Sessions.- MPI BugBench A Framework for Assessing MPI Correctness Tools.