小刀是小型的刀具，刀刃长度一般不超过成人的手掌，依结构可分为两大类＂直刀＂与＂折刀＂。

小刀是最贴近人民生活的工具，不管是在工作还是在日常生活中，都能看到其踪迹。

小刀一般由刀片和刀柄两大部分构成。由于目前在中国的主要产地集中在广东省阳江市，所以小刀的用语也多用阳江方言。以下是部分用语的对比:

A knife (plural knives) is a tool with a cutting edge or blade, hand-held or otherwise, with most having a handle. Some types of knives are used as utensils, including knives used at the dining table (e.g., butter knives and steak knives) and knives used in the kitchen (e.g., paring knife, bread knife, cleaver). Many types of knives are used as tools, such as the utility knife carried by soldiers, the pocket knife carried by hikers and the hunting knife used by hunters. Knives are also used as a traditional or religious implement, such as the kirpan. Some types of knives are used as weapons, such as the daggers used by commandos or the switchblades used by 1950s-era criminal gang members. Some types of knives are used as sports equipment (e.g., throwing knives). Knives are also used in agriculture, food harvesting etc, the sickle, the scythe and even the combine harvester are knives.