Australian Federal Police chief Andrew Colvin is standing down after 30 years in law enforcement.
Mr Colvin will leave the force at the end of September, when his five-year contract expires.
"I believe this is the right decision for me, for my family, and for the AFP," he said in a statement on Monday.
"It is with enormous pride that I have led the AFP for the past five years, a time during which we have achieved incredible success against a range of crimes both at home, and abroad."
Mr Colvin said he made the decision earlier this year, told the secretary of the prime minister's department before the election, and the responsible minister soon afterward.
"I want to say thank you to the AFP for embracing the changes I believe were so necessary in becoming the best organisation that we can be," he said.
"I consider myself extremely fortunate to have been a part of this organisation for almost the entirety of my working life and to work alongside the most dedicated and professional men and women."
He acknowledged the work of federal police officers took its toll.
"We have a privileged role in society but it comes at a cost," the commissioner said.
"This will continue to be one of our greatest challenges going forward."
Home Affairs Minister Peter Dutton praised the outgoing police chief.
"I thank Andrew for his inspirational leadership, diligence and hard work in protecting the community, and on behalf of all Australians, thank him for making Australia a safer place," Mr Dutton said.
Mr Colvin joined the AFP in 1990, spending most of his early career in Sydney investigating serious and organised crime.
He co-ordinated the AFP's response to the 2002 Bali bombings, along with two other deadly terror attacks in Jakarta.
Mr Colvin was awarded an Order of Australia for his efforts.
"I thank AFP Commissioner Andrew Colvin for his service and sacrifice - both as commissioner of the AFP for the past five years and his 30 year career in law enforcement," Labor's Kristina Keneally said.
"I wish him and his family all the best for the future."
The federal government has begun the search for a replacement.
Australian Associated Press