The year-long post is based at the NT Studio, where de Angelis will focus on her own work as well as offering support to other theatre-makers developing work there.
She will also, according to the National, "bring a writer's perspective to the creative planning" of the organisation.
April de Angelis' plays include Jumpy (Royal Court and West End), Hush, Havana and Wild East (Royal Court), A Laughing Matter (Out of Joint/National Theatre) and Gastronauts (Royal Court Upstairs).
The National has also today announced further details of its 2014 summer season:
Joining Helen McCrory in the cast of Medea in the Olivier (14 July-4 September) will be Michaela Coel, Danny Sapani and Cath Whitefield. The production will be directed by Carrie Cracknell and designed by Tom Scutt.
Cillian Murphy will be joined in the cast of Enda Walsh's Ballyturk by Mikel Murfi and Stephen Rea. The play runs in the Lyttelton Theatre for a five-week season from 11 September to 11 October.
The cast of Polly Stenham's new play Hotel, which runs in the NT Shed from 31 May-2 August, will include Ntonga Mwanzi and Susan Wokoma. Directed by Maria Aberg, the "tropical thriller" sees a family retreat to a "perfect desert island escape", but storm clouds are gathering.
The National's latest season of Platform discussions includes Alan Ayckbourn (10 April), Alan Bennett (7 May), Sam Mendes (19 May), Michael Palin (2 June) and Enda Walsh (19 September).