We propose the Unified Automata Processor (UAP), a new architecture that provides general and efficient support for finite automata (FA). The UAP supports a wide range of existing finite automata models (DFAs, NFAs, A-DFAs, JFAs, counting-DFAs, and countingNFAs), and future novel FA models. Evaluation on realistic workloads shows that UAP implements all models efficiently, achieving line rates 94.5% of ideal. A single UAP lane delivers line rates 50x greater than software approaches on CPUs and GPUs. Scaling UAP to 64 lanes achieves FA transition throughputs as high as 295 Gbps, more than 100x higher than CPUs and GPUs, and even exceeding ASIC approaches such as IBM's RegX by 6x. With efficient support for multiple input streams, UAP achieves throughputs that saturate even high speed stacked DRAM memory systems.The UAP design and implementation is efficient in instructions executed, memory references, and energy. UAP achieves a 1.2 Ghz clock rate (32nm TSMC CMOS), and a 64-lane UAP requires only 2.2 mm 2 and 563 mW. At these levels of performance and energy-efficiency, UAP is a promising candidate for integration into generalpurpose computing architectures.