West Side Park was the name used for two different ballparks that formerly stood in Chicago, Illinois. They were both home fields of the team now known as the Chicago Cubs of the National League. Both ballparks hosted baseball championships. The latter of the two parks, where the franchise played for nearly a quarter century, was the home of the first two world champion Cubs teams, the team that posted the best winning percentage in Major League Baseball history and won the most games in National League history (1906), the only cross-town World Series in Chicago (1906), and the immortalized Tinker to Evers to Chance double-play combo. Both ballparks were primarily constructed of wood.

The Chicago Cubs are an American professional baseball team based in Chicago. The Cubs compete in Major League Baseball (MLB) as part of the National League (NL) Central Division. The club plays its home games at Wrigley Field, which is located on Chicago's North Side. They are one of two major league teams based in Chicago, alongside the American League (AL)’s Chicago White Sox. The Cubs, first known as the White Stockings, were a founding member of the NL in 1876, becoming the Chicago Cubs in 1903.