A many-core microprocessor or many-core processor is a microprocessor that is comprised of a large number of processor cores with the goal of achieving higher degree of explicit parallelism. The cores need not be identical nor necessarily fully-featured. Many-core processors often focus on optimizing specific aspects such as power or throughput (i.e. optimized for specific types of algorithms or tasks) at the expense of other characteristics (e.g. serial code performance).

The term differs from a multi-core microprocessor which typically contains homogeneous cores designed to deliver high performance for both serial and parallel code, preventing it from making the kind of sacrifices a many-core microprocessor can. The term "many-core" does not denote a specific number of cores but rather their capabilities and intended tasks. For example the Core i7-6950X, a deca-core processor would generally be considered a multi-core processor but not a many-core processor, while MIT's 16-core RAW and Tilera's 64-core TILE64 would be both.