This book constitutes the proceedings of the First International Workshop on Mechanism Design in Social Networks, MNet 2024, held in conjunction with IJCAI 2024, in Jeju, South Korea, on August 4, 2024.The 5 full and 3 short papers included in these proceedings were carefully reviewed and selected from 21 submissions. They focus on providing an internationally respected forum for scientific research tackling the fundamental challenges of mechanism design in social networks.