打气筒是一种单向输出泵，主要用于给自行车、球等物品注入气体。

一般的打气筒都会有一个圆筒形的泵体，泵体内有一个活塞，活塞连接着T字形的手柄，泵体另一端用软管连接，软管末端链接需要打气的物品。接口一般都有防止漏气的装置（如自行车的气门芯，因此需要使用专门的金属接头衔接气筒软管与需要打气的物品。

打气筒通常可分为脚踏式、手持式、站立式等等，另外也有使用电机驱动的电动式打气筒。另外一般的打气筒是只能在按压手柄的时候压入空气，最近也出现了在拉出手柄时同样可以压入空气的双动泵。

A bicycle pump is a type of positive-displacement pump specifically designed for inflating bicycle tires. It has a connection or adapter for use with one or both of the two most common types of valves used on bicycles, Schrader or Presta. A third type of valve called the Dunlop (or Woods) valve exists, but tubes with these valves can be filled using a Presta pump.