Bird - who, as Heathrow's head of media relations, reported to director of comms Ben Morton - leaves Europe's busiest airport to join BTP later this month.
She will take the new role of head of media and marketing - the organisation's top comms post, overseen by deputy chief constable Andy Trotter.
BTP created the post in response to its heightened media profile after the 7/7 terror attacks last year.
She will oversee a department of nine, including marketing manager Tom Walsworth and media and customer relations manager Simon Lubin.
