Western New York is a phrase often used within the state of New York, but it really has no consistent definition.
In Buffalo and its immediate surrounding areas, the term encompasses only the westernmost eight counties of New York. As you go farther east, though, the definition generally expands accordingly. Rochester, for example, is usually considered to be part of Western New York everywhere except in Buffalo. At the extreme, some residents include Syracuse in the area, although it's more often considered part of Central New York.
The following regions include parts of Western New York: