The goal of this research is to create a decision-making process for sustainable supplier selection and order allocation that is known as Fermatean Fuzzy Sets-Based Decision Making (FFS-DMS). The Improved Salp Swarm Optimization (ISSO) approach is used to pick suppliers and allocate the best order quantities. The suggested FFS-ISSA-DMS technique's viability and efficacy are proven through empirical experiments. With an astounding 99.81% accuracy rate, this method outperforms other models that are already in use in this situation.