He will move into the role when current CEO Sol Trujillo stands down.
Thodey, 54, has been a senior executive at Telstra for eight years.
He joined the company from IBM where he was CEO of its A/NZ operations.
He is responsible for Telstra's corporate, government and large business customers in Australia, TelstraClear in New Zealand and its international sales division.
Thodey said he was looking forward to building on the strong foundation left by Trujillo's four years at the helm.
"Telstra is a great Australian company with terrifically capable and committed people," said Thodey.
"This company plays an important role in Australia, keeping millions of people reliably in touch across this vast country and across the world.
"Our strategy remains unchanged: to continue to provide customers with world-class products and services.
"The key to Telstra continuing to win and to serve customers will be finishing our transformation that started nearly four years ago.
"Completing the transformation will enable us to deliver a superior customer experience and the financial outcomes that our shareholders expect," he added.
In a separate hiring, Donald McGauchie AO resigned as chairman and from the Telstra board and he will be replaced by Catherine Livingstone AO, a Telstra board director since 2000.
McGauchie said it had been an honour to be Telstra chairman for the past five years.
It was also announced that Peter Willcox had tendered his resignation to the board due to his concern that the James Hardie judgment may cause embarrassment to the company.
However, the board has asked him to remain as a director until the AGM in November because of his contribution to a number of current issues.
Peter has agreed to do so but will not stand for re-election at the 2009 AGM.