Previously called Hanslape from the time of the Domesday Book in 1086 right through to the Victorian period, it refers in Old English to a muddy place or slope belonging to a man called Hama.
There was once a castle in the parish (that later became Castlethorpe), that was the seat of Lord Mauduit. In 1215 Mauduit had started a rebellion against King John of England and was defeated in battle by the king's men. Following King John's death however, Mauduit reclaimed his seat and founded a grand park in the parish, remnants of which can still be found in Hanslope today. The castle, however, has long since disappeared.
In the medieval period it was a market town, granted in 1293.
In the Victorian period, most of the inhabitants of the village were employed in the manufacture of lace. This was a common trade in Buckinghamshire, and Hanslope lace was renowned for being a particularly fine example.