The 2005 Slammiversary was a professional wrestling pay-per-view (PPV) event produced by the Total Nonstop Action Wrestling (TNA) promotion, which took place on June 19, 2005 at the TNA Impact! Zone in Orlando, Florida. It was the first event under the Slammiversary chronology and the sixth event in the 2005 TNA PPV schedule. Nine professional wrestling matches, three of which featured championships, and one pre-show match were featured on the event's card. The event commemorated TNA's third anniversary, after forming on June 19, 2002.

The Impact Zone is the nickname for any one of three sound stages at Universal Studios Florida in Orlando; they received this nickname due to their use by the professional wrestling promotion Total Nonstop Action Wrestling (TNA), who taped their weekly television series Impact! at the complex for much of its first two decades of existence.