The billhook (also brishing hook, pruning bill, etc.) is an agricultural cutting tool used to cut small woody material such as shrubs or branches. The blade is generally forward-curved, with a single edge on the inside of the curve. The billhook may be short or long-handled depending on the pattern size. Similar implements through the world are known as fascine knives and gandasas; an American long-handled billhook exists, known as a kaiser blade.

The use of the billhook dates back to Bronze Age Greece, and the tool remains in common use throughout Western Europe.

The militarized version of the billhook, mounted onto a long handle as a pole weapon, is known as the bill.