The Wisconsin Timber Rattlers are a Minor League Baseball team of the Midwest League and the High-A affiliate of the Milwaukee Brewers. They are located in Grand Chute, Wisconsin, a town on the outskirts of Appleton in the Fox Cities, and are named for the timber rattlesnake, which is more commonly found in southwest Wisconsin. The team plays their home games at Neuroscience Group Field at Fox Cities Stadium, which opened in 1995. They previously played at Goodland Field from their founding in 1958 until the end of the 1994 season.

High-A, officially Class High-A, formerly known as Class A-Advanced, and sometimes abbreviated "A+" in writing, is the third-highest level of play in Minor League Baseball in the United States and Canada, below Triple-A and Double-A, and above Single-A. There are 30 teams classified at the High-A level, one for each team in Major League Baseball (MLB), organized into three leagues: the Midwest League, Northwest League, and South Atlantic League.