"To release control of something you are so passionate about is never easy and I am profoundly aware of the trust the members, fans and indeed the Wollongong community is putting in me.
"I am confident we can build on the foundations laid over many years and deliver to this city a club that will thrive and continue to provide members and fans with great entertainment for many years to come."
Spenceley's arrival at the Hawks comes a year before the NBL's likely expansion from eight to 10 teams.
"This is a great moment for the Hawks, the Illawarra community and basketball at all levels throughout the region," NBL boss Fraser Neill said.
"The Hawks have an incredible opportunity to reinvent themselves, and under the guidance of James Spenceley they have the ability to grow and thrive in tandem with the NBL," he added.
In recent weeks the Hawks have appointed a general manager and re-signed coach Gordie McLeod and free agents Oscar Forman, Tim Coenraad and Larry Davidson.