Since 2002, Xavier Bray has been assistant curator of 17th- and 18th-century European paintings at the National Gallery, London. He completed his doctoral dissertation, "Royal Religious Commissions as Political Propaganda in Spain under Charles III," at Trinity College, Dublin, in 1999.

Between 1998 and 2000, he was assistant curator at the National Gallery, London, where he co-curated exhibitions such as Orazio Gentileschi at the Court of Charles I (1998-1999), A Brush with Nature: The Gere Collection of Landscape Oil Sketches (1999), and The Image of Christ: Seeing Salvation (2000). He was also the curator of a focus exhibition on Goya's Family of the Infante Don Luis (2001-2002).

From 2000 to 2002 Bray was the curator of paintings at the Museum of Fine Arts in Bilbao, where he organised exhibitions such as An Intimate Vision - Women Impressionists (2001-2002) and Vicente López: Court Painter to Fernando VII (2002). He returned to the National Gallery, London, in 2002 and was the co-curator of El Greco (2004), Caravaggio (2005), and Velazquez (2006). The Sacred Made Real: Spanish Painting and Sculpture, 1600-1700 (2009) was the first solo exhibition organised by Bray.