Mohamad Fuzi Harun has been appointed inspector-general of police, taking over from Khalid Abu Bakar.
Prior to this, Fuzi was the head of the police special branch.
Fuzi, 58, was appointed ahead of deputy IGP Noor Rashid Ibrahim, who is scheduled for retirement next year.
Home Minister Ahmad Zahid Hamidi announced the appointment today, ahead of the outgoing Khalid's retirement ceremony.
"The government, through the police commission has decided to appoint Fuzi to replace Khalid," said Zahid.
Khalid retired as a policeman today after 41 years of service, upon reaching 60 years of age.
Asked whether there was a special reason for Fuzi's appointment as IGP, Zahid simply repeated that "the government has decided".
Meanwhile, Zahid announced that Criminal Investigation Department (CID) director Mohd Mokhtar Mohd Shariff will replace Fuzi as the Special Branch chief.
Noor Rashid, on the other hand, has been retained as deputy IGP but will receive a pay grade promotion.
Fuzi, when asked whether his promotion has to do with counter-terrorism efforts, said terrorism was not a localised issue.
"It's a global issue. This will be emphasised by not only me but the government, too," he said.
Fuzi also confirmed that 343 new posts have been created to boost counter-terrorism efforts.
Previously, there was intense speculation that Khalid's tenure would be extended following Putrajaya's decision to extend the tenure of the chief justice and Court of Appeal president.
He is known for his active role on social media, often tweeting instructions to his subordinates to act against certain individuals or groups and issuing informal warnings to Malaysians.
Civil rights activists have often criticised the police chief for using the social media platform to curb free speech.