Mylrea has been acting in the role since former director of comms Ed Williams left during the summer to join Edelman as UK CEO.
The role is thought to be the best-paid job in public sector PR. The BBC's most recent figures revealed that Williams earned £225,940 in 2010.
Mylrea said: 'Ed Williams is a tough act to follow. I'll be looking over the next few weeks to see how we can implement the savings we have to deliver, and make sure we tell the BBC story in the best way possible.'
Mylrea will report to chief operating officer Caroline Thomson. He led comms around Thursday’s publication of the BBC’s cuts plan, ‘Delivering Quality First’.
Before joining the BBC in 2010 as head of press and media relations, Mylrea was comms director for the Department for International Development.
He has previously worked as director of media relations at Transport for London, where he led communications around the 2005 bomb attacks, and was also head of media for Oxfam.
Mylrea began his career in local newspapers in Manchester and Southend before joining Reuters.
He is also president of the CIPR.
As revealed in July, the BBC is set to make around 30 redundancies from its 185-strong comms unit.