The Big O Tournament is an international roller derby tournament hosted by Emerald City Roller Derby, a 501c3 organization founded in Lane County in 2007. The tournament includes women’s, men’s, and junior roller derby teams from both the U.S. and around the world, and has grown continually since its inception in 2011.

The tournament is held annually at the Lane Events Center during the first weekend in May.

The Big O was founded upon the premise of showcasing the talent of, and supporting inclusion in, roller derby at all levels and of play, gender, and age. As such, we provide a unique gaming experience for roller derby teams of different rankings, locations, and competitive goals.

The Big O has grown to become the early-season tournament for WFTDA and MRDA teams to establish rankings.

The tournament welcomes more than 30 teams from around the globe every year, including top-ranked men’s and women’s teams. More than 4,000 people participate including skaters, officials, vendors, spectators, and other support staff.