María del Pilar López de Ayala Arroyo (Madrid, September 18, 1978) is a Spanish actress.

She began working in television series such as Menudo es mi padre (1996). From there she went to Al salir de clase (1997) and soon made the leap to film with Fill Me with Life (2000). Her character of Rocío, an upper middle class Cadiz woman in the film Besos para todos (2000), earned her a Goya nomination for best new actress. But her definitive confirmation came with the leading role in Mad Love (2001) of Vicente Aranda, which earned her a Goya award for best female performance playing Juana and the Concha de Plata for best female performance at the San Sebastian Film Festival. Her new status as a star of Spanish cinema led her to be chosen by the cava brand Freixenet to star in its well-known Christmas spot.

In 2005 she released Obaba (2005) of Montxo Armendáriz, a film for which she obtained a new nomination at the Goya Awards, this time as Best Supporting Actress. Obaba (2005) was nominated by Spain for the 2005 Oscars, although in the end it was not nominated among the five candidates for Best Foreign Film.

Other titles in her filmography are The Bridge of San Luis Rey (2004), Captain Alatriste: The Spanish Musketeer (2006), Walking Vengeance (2008) or Intruders (2011) with Clive Owen. Her latest film to date is Agadah (2017).

Away from cinema, Pilar went to New York to study Art History.