Javier Marías was born in Madrid. His father was the philosopher Julián Marías, who was briefly imprisoned and then banned from teaching for opposing Franco. Parts of his childhood were spent in the United States, where his father taught at various institutions, including Yale University and Wellesley College. His mother died when Javier was 26 years old. He was educated at the Colegio Estudio in Madrid.

Marías began writing in earnest at an early age. "The Life and Death of Marcelino Iturriaga", one of the short stories in While the Women are Sleeping (2010), was written when he was just 14. He wrote his first novel, Los dominios del lobo (The Dominions of the Wolf), at age 17, after running away to Paris.

Marías operates a small publishing house under the name of Reino de Redonda. He also writes a weekly column in El País. An English version of his column "La Zona Fantasma" is published in the monthly magazine The Believer.

Celebrated as one of the greatest writers of his generation, Javier Marias is best known for his spy trilogy, "Your Face Tomorrow", which has been compared to Proust and hailed as one of the great modern European novels. In his first short story collection for fifteen years, beautifully translated by Margaret Jull Costa, he brings together tales which span his entire writing career from the 1960s to the present. Marias' characters are slippery, and they live on the edges of society: a tramp, a butler, a bodyguard, a ghost. They threaten the everyday, rational world, and, compelled by desperation, are driven to perverse acts of obsession. In the title story an obscenely fat man fixated with his much younger lover endlessly videotapes her every move, and, in a chance midnight rendezvous, confides his shocking plans for her to a stranger; in "The Resignation Letter of Senor of Santiesteban" a ghost is condemned to repeatedly resign from his job; and in perhaps the most perfectly conceived story, when a man of impeccable taste and refinement meets his doppelganger at a work dinner ('it was like dining opposite mirror made flesh'), he starts changing his dress and behaviour, in ways he previously would have abhorred, to mark the difference, only to find, at the next work convention, that his ghoulish twin has done exactly the same. Mesmerising, unexpected and disturbing, these creepy, haunting stories inspire the reader to look at the normal things of life aslant.