Castile or Castilia can mean:

• Kingdom of Castile, the historical kingdom from the 9th to the 13th century
• Crown of Castile, the historical Kingdom formed in 1230 from the union of the Kingdom of Castile and Kingdom of León
• Castile-La Mancha, an autonomous community of Spain formed in 1982, composed of five provinces: Albacete, Ciudad Real, Cuenca, Guadalajara and Toledo
• Castile and León, an autonomous community of Spain formed on February 25, 1983, composed of 9 provinces, six Castilian and three Leonese: León, Zamora, Salamanca, Ávila, Burgos, Palencia, Segovia, Soria and Valladolid
• Old Castile, the political name of the region formed by Santander, Burgos, Logroño, Soria, Segovia, Ávila, Valladolid and Palencia. It had some territorial changes in its History, and had this name from 18th century to 1983. It no longer exists
• New Castile, the political name of the region formed by Ciudad Real, Cuenca, Guadalajara, Madrid, Toledo and part of Albacete. It took this name in the 18th century and disappeared with democracy. It no longer exists

Other

• Real Madrid Castilla, a Spanish football team. It is the reserve team of Real Madrid
• Castile soap, a name used in English-speaking countries for soap made exclusively from vegetable oil
• Castilia (butterfly), a butterfly genus
• Castella, a kind of sponge cake popular in Japan. The name comes from the Portuguese phrase pão de Castella, meaning "bread from Castile"