The WDL Junior Division (WDLJD) is the branch of the Waterbending Duelist League for competitors who are under the age of 13 or as high as 16. The WDLJD was created in 223 ASC to give younger waterbenders a chance to get the feel for the WDL outside the main league. At age 13, WDLJD competitors begin getting consideration for the main league; if officials believe a competitor between 13 and 16 is overmatching their opponents, they will be promoted to the main league. At age 16, WDLJD athletes are automatically promoted.

Like the WDL, the WDLJD offers a regular season and a playoff, though matches and seasons are of shorter length. It is also open to both male and female waterbenders, and has a large amount of parity.