The "steroid era" is a colloquial term applied to a period of time in the late 20th and early 21st centuries when performance-enhancing drug (PED) use was widespread in American professional baseball. While only a few players actually admitted or can be proved to have used PEDs during this time, accusations of use and public speculation was widespread.

One of the precipitating events behind rising public and media speculation about PED use among professional baseball players was a series of dramatically increased statistics among several players, including a trend toward increased home run hitting in the 1990s and early 2000s. Not only were pro players hitting more runs, but some specific players, such as Mark McGwire, Sammy Sosa and Barry Bonds, were breaking records that had been held for decades, setting new records, and breaking those in turn. McGwire and Sosa were even named the Sports Illustrated Sportsmen of the Year in 1998. However, some of the players involved with this period of pro baseball, including McGwire and Bonds, have been definitively or anecdotally linked with PED use.