Byron is a city in Ogle County, Illinois, United States, probably best known as the location of the Byron Nuclear Generating Station, one of the last nuclear power plants commissioned in the United States. Byron is located in Byron Township, along the Rock River. The population was 3,753 at the 2010 census, up from 2,917 at the 2000 census. The town bills itself as the "Gateway to the Rock River Valley".

Albert Goodwill Spalding was an American pitcher, manager, and executive in the early years of professional baseball, and the co-founder of A.G. Spalding sporting goods company. He was born and raised in Byron, Illinois, yet graduated from Rockford Central High School in Rockford, Illinois. He played major league baseball between 1871 and 1878. Spalding set a trend when he started wearing a baseball glove.