We examine the dimensions of the sports market in the United States.We investigate sports participation, sports viewing, and the supply and demand sides of the sports market. Our estimates of the value of economic activity in the sports market rang from $44 to $60 billion in 2005. The 49,169 firms in the industry employed just over one million workers. About 118 million people participated regularly in sports in 2005, and more than 277 million individuals attended spectator sporting events.