A network switch to support scalable and flexible access control list (ACL) lookup comprises a packet processing pipeline including a plurality of packet processing units each configured to generate a master key for an ACL lookup request to a memory pool and process a received packet based on ACL search results. The network switch further includes said memory pool including a plurality of memory groups each configured to maintain a plurality of ACL tables to be searched in one or more SRAM memory tiles of the memory group, accept and format the master key generated by the packet processing unit into a compact key based on a bitmap per user configuration, hash the formatted compact key and search the ACL tables stored in the one or more SRAM memory tiles using the formatted compact key, process and provide the ACL search results to the requesting packet processing unit.