Stephen Longespée (c. 1216 – 1260) was an English knight who served as Seneschal of Gascony and as Justiciar of Ireland.

He was a cousin of the King Henry III of England.

His wife Emmeline was an heiress of her grandfather Walter de Riddlesford, and brought possessions in Connacht and Leinster in Ireland.

[2] In 1255, Longespée was appointed the Seneschal of Gascony, where his administration was hampered with disputes with Lord Edward.

When Lord Edward reluctantly recognised the Provisions of Oxford in 1258, Longespée was one of the four counsellors given to accept the reform program.