Telstra replaced two leaders on Friday, with chairman Donald MCGauchie resigning on the same day new CEO David Thodey was appointed.
Board member Catherine Livingstone replaces McGauchie as chair, effective immediately.
Thodey's previous role was Telstra's enterprise and government director, and he begins his tenure as CEO when Sol Trujillo leaves Telstra to return to the US.
Thodey, who joined Telstra eight years ago, was CEO at IBM's Australian and New Zealand operations.
"This company plays an important role in Australia, keeping millions of people reliably in touch across this vast country and across the world," Thodey said in a statement.
"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," Thodey said.
McGauchie resigns after five years as Telstra chairman.
"Telstra's strength and ongoing performance are the paramount priority. It is my view that speculation on my tenure was a distraction to the business. Nothing should be allowed to get in the way of David and the management team getting on with the important job ahead of them," McGauchie said in a statement.
Telstra's CFO, John Stanhope, has been appointed an executive director of the board and board member Peter Willcox has resigned due to his concern that the James Hardie judgment may cause Telstra embarrassment.