袭击，突袭，是一种攻击行动或军事手段，常常是趁目标不注意或无特别防范之处打击它。单字袭有时也是同样的意思。

袭击是历史久远的军事战术，成功的袭击是攻其不备，是故，偷袭也是一种很常见的说法。

87年时的例子，东汉护羌校尉傅育想要讨伐叛羌中以迷吾为首的烧当羌，组织了河西、陕西等几个郡准备合攻。但傅育没有等到联军会师就独自进军，夜晚追敌时便被迷吾袭击成功。「……育请发诸郡兵数万人共击羌。未及会，三月，育独进军。迷吾闻之，徙庐落去。育遣精骑三千穷追之，夜，至三兜谷，不设备，迷吾袭击，大破之，杀育及吏士八百八十人。……」

Raid, also known as depredation, is a military tactic or operational warfare mission which has a specific purpose and is not normally intended to capture and hold terrain, but instead finish with the raiding force quickly retreating to a previous defended position prior to enemy forces being able to respond in a co-ordinated manner or formulate a counter-attack. A raiding group may consist of combatants specially trained in this tactic, such as commandos, or as a special mission assigned to any general troops. Raids are often a standard tactic in irregular warfare, employed by warriors, guerrilla fighters, or other irregular military forces.