Álvaro Pires de Castro

The Count of Arraiolos
Coat of arms of Álvaro Pires de Castro
Constable of Portugal
In office
1382–1384
MonarchFerdinand I of Portugal
Preceded byposition established
Succeeded byNuno Álvares Pereira
Personal details
Bornc. 1310
Died11 June 1384(1384-06-11) (aged 73–74)
Lisbon, Portugal
NationalityPortuguese

Álvaro Pires de Castro (c. 1310 – 11 June 1384 in Lisbon) was a powerful Galician-Portuguese nobleman, stem of the Portuguese branch of the House of Castro. He was the first Count of Viana (da Foz do Lima), the first Count of Arraiolos and the first Constable of Portugal.