The Fox River Valley is a region in greater Chicagoland. It generally is centered on the Fox River, a major tributary of the Illinois River, and sits on the outer edge of the greater region. Like many other Chicagoland regions, it has two major anchors: the cities of Elgin and Aurora.
The Fox River Valley is Chicagoland's westernmost region and is generally defined as all communities close to or immediately on the river itself. Almost all definitions of the region include everything between the anchor cities of Elgin and Aurora though, in a broad sense, all communities from the end of the Chain O' Lakes to the meeting of the Fox and Big Rock Creek (just south of Plano) could be considered part of the region.
In many respects, you can easily see similarities between this region and the Rock River Valley region farther west in Northern Illinois. Both areas relied heavily on their rivers and were home to manufacturing and industrial centers for many years. However, while the Rock River Valley struggle, the Fox River Valley was able to adapt based on its easy access to Chicago. Many communities, such as the Tri-Cities of St. Charles, Geneva and Batavia, are essentially modern Chicago suburbs and older communities, such as Elgin and Aurora, have more diversified economies than many other large cities in Chicago.