护甲，又称防弹护甲，华人圈内通称防弹衣或防弹背心，而在香港、澳门和广东则称之为避弹衣。

与古代盔甲相似，都是用作防御武器的攻击。

防弹衣是用来吸收枪枝发射的子弹或爆炸的碎片的冲击力量的个人身体护具，不同种类有不同的运行原理，分为全软质及加强/复合式。

A flak jacket or flak vest is a form of body armor designed to provide protection from case fragments ("frag") from high explosive weaponry, such as anti-aircraft artillery ("flak" a German contraction for "Fliegerabwehrkanone" (aircraft-defense gun)), grenades, some round shot used in shotguns and land mines and other lower-velocity projectiles. It is not designed to protect against bullets fired from small-arms such as rifles or handguns. However, certain flak jackets are able to sustain certain gunshots, dependent on the armor, the gun, and the distance that the bullet has travelled.