The Menomonee Valley or Menomonee River Valley is a U-shaped land formation along the southern bend of the Menomonee River in Milwaukee, Wisconsin. Because of its easy access to Lake Michigan and other waterways, the neighborhood has historically been home to the city's stockyards, rendering plants, shipping, and other heavy industry. It was also a primary source of pollution for the river.
Glacial meltwater formed the Menomonee Valley over 10,000 years ago when the Lake Michigan Lobe of the Wisconsin Glaciation retreated and eroded a swath four miles (6 km) long and half of a mile wide. Today, it is roughly bounded by the 6th Street Viaduct near the river confluence and Miller Park stadium to the west. The valley effectively cuts Milwaukee in half, limiting access to a handful of viaducts that span the chasm.
With a historically predominant white south side and black near north side, the valley has been perceived as a social and racial divide during times of civil unrest. In the 1960s, Father James Groppi organized protests against segregation in Milwaukee and led a number of fair housing marches across this symbolic divide. The 16th Street Viaduct has since been renamed in his honor.