NBL1 West, formerly the State Basketball League (SBL), is a semi-professional basketball league in Western Australia, comprising both a men's and women's competition. In 2020, Basketball Western Australia partnered with the National Basketball League (NBL) to bring NBL1 to Western Australia. NBL1 replaced the former SBL to create more professional pathways and opportunities for males and females playing basketball in Western Australia. As a result, the SBL became the west conference of NBL1.
The State Basketball League originated in 1972 as the District Competition. The District Competition was introduced by the Western Australian Basketball Federation (WABF) as an 'elite' competition held on Friday nights, featuring eight Perth-based associations from the prominent districts of Perth, Swan Districts, Tangney/Willetton, Subiaco, East Perth, Cockburn, Stirling, and Claremont.
In 1987, plans were put in place to expand the competition and include several country teams. In 1988, it was decided to form a State Basketball League for both men and women, and in 1989 the SBL made its debut season with three new franchises established in country areas: Rainbow Coast Raiders from Albany, Batavia Buccaneers from Geraldton, and Souwest Slammers from Bunbury. Kanyana Kings from Mandurah and Goldfields Giants from Kalgoorlie joined in 1990.
In 2017, the SBL shifted to the 40-minute game format in-line with FIBA, with games consisting of ten minute quarters as opposed to the twelve minute quarters under the previous 48-minute format.
Due to the COVID-19 pandemic, the 2020 SBL season was cancelled and later replaced by the amateur-based West Coast Classic.
In October 2020, Basketball Western Australia and the National Basketball League (NBL) announced a new partnership to bring NBL1 to Western Australia in 2021, with NBL1 replacing the SBL. The SBL was officially renamed NBL1 West and became the west conference of NBL1.