|King of Castile and Toledo|
|Reign||5 October 1214 – 6 June 1217|
|Born||14 April 1204|
|Died||6 June 1217 (aged 13)|
(m. 1215; annulled 1216)
|House||Castilian House of Ivrea|
|Father||Alfonso VIII of Castile|
|Mother||Eleanor of England|
Henry I of Castile (14 April 1204 - 6 June 1217) was king of Castile. He was the son of Alfonso VIII of Castile and Eleanor of England, Queen of Castile (daughter of Henry II of England and Eleanor of Aquitaine). He was the brother of Berenguela and Mafalda of Castile.
In 1211, Henry became heir to the throne when his older brother Ferdinand suddenly died.
In 1215, Henry married Mafalda of Portugal, daughter of Sancho I of Portugal. As he was very young, the marriage was not consummated, and it was dissolved in 1216 by Pope Innocent III on grounds of consanguinity. In the same year, Henry became betrothed to his second cousin Sancha, heiress of León.
Henry died in Palencia in 1217 at the age of 13, killed by a tile coming off a roof. His sister Berengaria succeeded him, before renouncing the throne in favour of her son Ferdinand III. His body was buried at Las Huelgas monastery in Burgos.