The screenings of the first seven films will start with three Wednesday and four on Thursday, culminating with "Harry Potter and the Deathly Hallows - Part 2" at 12 a.m. Friday.
The select theaters are in Illinois, Ohio, Minnesota, Nebraska, North Dakota and Wisconsin. The price for all eight films is $45.
"Harry Potter and the Deathly Hallows: Part 2" depicts Harry's final confrontation with the forces of evil Lord Voldemort -- an epic showdown rendered, for the first time in the series, in 3D.
The first movie was released in 2001.
In the Chicago area, Marcus Theatres lists Gurnee Cinema and Orland Park Cinema as running the marathon.
The Associated Press contributed to this report.
