Lockdown (2008) was a professional wrestling pay-per-view (PPV) event produced by the Total Nonstop Action Wrestling (TNA) promotion, which took place on April 13, 2008 at the Tsongas Arena in Lowell, Massachusetts. It was the fourth under the Lockdown chronology and fourth event in the 2008 TNA PPV schedule. Eight professional wrestling matches, two of which for championships, were featured on the card. In the tradition of Lockdown events, every match took place inside a six sided steel structure known as the Six Sides of Steel.