Barry O'Farrell is to step down from his role as chief executive of Racing Australia for yet to be revealed professional reasons.

RA chairman chairman Greg Nichols announced on Friday, O'Farrell would leave the organisation.

"Barry recently advised me that, for professional reasons he's currently unable to disclose, he was no longer able to continue in the role," Nichols said.

RA operations chief executive Myles Foreman will assume the role in an acting capacity with the board to consider a replacement process at its November meeting.

A former Liberal premier of NSW who joined RA in January 2017, O'Farrell is the chairman of Wests Tigers NRL club and also holds positions as chairman of the NSW Rugby League Foundation, president and chair of Diabetes Australia and is a Trustee of the Sydney Cricket Ground.