Nadine Thompson will join the opera company on 1 August after nine years at the Tate's comms department. She had worked her way up from a PRO position to lead the Tate's comms team.
In the new role, Thompson will report into ENO chief executive Loretta Tomasi.
The ENO, based near London's Covent Garden, is currently Britain's only full-time repertory opera company.
As well as managing the firm's media, PR and brand activity, Thompson is charged with targeting opinion formers, liaising with sponsors, lobbying and handling events management. Online media will also be a key focus in the coming months.
'Widening audiences through new media is a challenge that ENO is embracing with initiatives such as ENO Interactive and the online digital opera guide,' said head of press Jane Livingston.
Last month, as part of its PR activities, the ENO staged the world's first aerial operatic performance, in conjunction with television channel Sky Arts. Opera star Lesley Garrett was suspended 50 metres above the Tower of London to promote the launch of the new Sky Seats Extra scheme, which offers reduced-price opera tickets to the public.
While at the Tate, Thompson led the Transforming Tate Modern project and managed the launch of Tate Modern and the annual Turner Prize award.
Before joining Tate in 1999, Thompson was deputy to the heads of press and marketing at the Royal Academy of Arts.