自行火炮（英语：Self-propelled artillery），指使用车辆底盘自备动力，无需其他车辆牵引的火炮，大多有轻装甲保护，火炮一般为榴弹炮、迫击炮、加农炮、反坦克炮、火箭炮或高射炮等。有别于一般火炮需要利用其他车辆，兽力或者是人力移动。

近代设计的新趋势是在需要牵引的火炮加上小型汽油引擎的辅助动力设备APU，除了能够协助射击时的操作，还可以做短距离的行动，但是这一种设计并未包含在自走炮的归类当中，仍属于牵引火砲如芬兰155 GH 52 APU。

Self-propelled artillery (also called mobile artillery or locomotive artillery) is artillery equipped with its own propulsion system to move towards its target. Within the term are covered self-propelled guns (or howitzers) and rocket artillery. They are high mobility vehicles, usually based on continuous tracks carrying either a large howitzer, field gun, a mortar or some form of rocket or missile launcher. They are usually used for long-range indirect bombardment support on the battlefield.