Daley joins the special health authority next week as chief operating officer.
He will report in to the HPA’s director of communications Lis Biranne and will head up a team of five.
Daley leaves behind a five-strong team under the leadership of head of external comms Kate Hewer, who returned from maternity leave earlier this year.
The HPA provides support and advice to the NHS, local authorities, and emergency services.
Prior to joining GSK, Daley worked at the Department of Health’s media centre as a press officer.
‘The move is a great opportunity at a time when public health is high on the media agenda,’ said Daley.