Kearns played 67 tests for the Wallabies and was a member of their 1991 and 1999 world Cup winning teams.
Since retiring, he has carved out a successful career in the corporate world and as a colourful rugby broadcaster.
"Phil has an impeccable international reputation both in the corporate sector and with his network of contacts throughout the rugby world," Rugby Australia chairman Hamish McLennan said in a statement on Wednesday.
"Phil will be front and centre of Rugby World Cup bid team and will lead our international relations to put Rugby Australia in the strongest possible position to win the right to host the 2027 showpiece."
Kearns was considered a hot favourite to replace Bill Pulver as Rugby Australia's chief executive in 2017 but was beaten to the job by Raelene Castle.
Castle resigned earlier this year and has been replaced by an interim CEO.
Australia has hosted the Rugby World Cup twice before. It was a co-host with New Zealand for the inaugural event in 1987 and had the sole rights in 2003.
France will host the next Rugby World Cup in 2023.
Russia announced last month they intended to bid for the 2027 event and had secured the high-powered backing of president Vladimir Putin.
Argentina withdrew their bid earlier this year.
(Reporting by Greg Stutchbury in Wellington; Editing by Richard Pullin)