The Ultimate Tag League is a professional wrestling round-robin tag team tournament held by DDT Pro-Wrestling. It was created in 2000 as the DDT Tag League (DDTタッグリーグ, DDT Taggu Rīgu) and was renamed KO-D (King of DDT) Tag League (KO-Dタッグリーグ, KO-D Taggu Rīgu) in 2001. In 2021, the tournament was brought back 16 years after the previous edition under its current name.