Peter V'landys is set to become the NRL's first full-time chairman and executive since the independent ARL Commission was created in 2012.
The appointment is expected to be confirmed as early as Thursday, after V'landys secured support from clubs, states and fellow commissioners.
He will leave Racing NSW when his long-service leave ends in November, concluding 22 years as its chief executive.
V'landys assumed that position in 2004 after 17 years leading NSW Harness Racing. He helped guide the industry through equine influenza and established The Everest in 2017.
Andrew Abdo's resignation as NRL CEO in May created the opening. V'landys had said only "Superman and Jesus added together" could replace him, while declining to discuss his own prospects.
Racing NSW said his initiatives generated $3.5 billion in new funding.
V'landys said: "Naturally, this is a very sad day for me. I have put my heart and soul into racing for 22 years."
Racing NSW chair Dr Saranne Cooke called him "the most effective and successful administrator in the history of Australian sport".