The news comes a day after Foxtel announces increase in subscribers, revenues.
Previously, Williams was CEO of Foxtel for ten years.
In a statement Williams said, he is confident that "I leave the company in a strong position and with good foundations for the future.It has been a privilege to work for News Corp across almost 20 years, and I have no doubt it will remain the most memorable element in my professional commercial life."
News Corp executive chairman Rupert Murdoch thanked Williams for his "nearly two decades of service to News Corp; but more importantly, for his loyalty and friendship to me and my family all of these years.
"From the early days when we opened Fox Studios Australia, to his tenacious work building Foxtel and FOX SPORTS into the powerhouse it is today, Kim has always operated with great integrity and skill.
"Kim has been a steady and courageous leader at a time when our businesses have faced unprecedented pressure and economic challenges," he said.
Williams was appointed CEO of News Corp Australia in 2011 after John Hartigan stepped down.