In next-generation high-speed networks, Elastic Optical Networks (EONs) play a promising role due to its more flexibility and optimal spectrum management. Some of the key facts of EON that have to be addressed are Routing and Spectrum allocation. In this paper, an efficient routing algorithm is proposed along with optimization of spectrum allocation for EON. Improved Bellman Floyd Warshall (IBFW) shortest path routing and Enhanced Shuffled Frog Leaping Algorithm (ESFLA) are used in our proposed work. Simulation results are compared with recent RSA algorithms with appropriate metrics where it achieves better spectrum utilisation and reduced number of blocking. © 2020, © 2020 Informa UK Limited, trading as Taylor & Francis Group.