NBL1 East, formerly the Waratah League, is a semi-professional basketball league in New South Wales and the Australian Capital Territory, comprising both a men's and women's competition. In 2021, Basketball New South Wales partnered with the National Basketball League (NBL) to bring NBL1 to New South Wales in 2022. NBL1 replaced the former Waratah League to create more professional pathways and opportunities for males and females playing basketball in New South Wales. As a result, the Waratah League became the east conference of NBL1. The league was previously a member of the Australian Basketball Association (ABA) from 2001 to 2008.

In 1991, the New South Wales Premier Division was established. In 2001, the league was rebranded as Waratah League when the league entered the Australian Basketball Association (ABA).

In 2021, Basketball New South Wales and the National Basketball League (NBL) announced a new partnership to bring NBL1 to New South Wales in 2022, with NBL1 replacing the Waratah League. The Waratah League was officially renamed NBL1 East and became the east conference of NBL1.

* Teams that transferred from the Waratah League.
** Teams that transferred from other NBL1 conference.