移动电话，又称“行动电话”、“流动电话”、「手提式电话机」或「手提电话」，简称「手机」，是可以在较广范围内使用的便携式电话，与固定电话（座机）相对。1990年代中期以前价格昂贵，只有极少部分经济实力较佳的人才买得起，而且体积庞大，因此又有大哥大的俗称。1990年代后期大幅降价，如今已成为现代人日常不可或缺的电子用品之一。

目前在全球范围内使用最广是的第三代移动通信技术。在台湾和中国大陆以GSM最为普及，CDMA和小灵通（PHS）手机也很流行。第二代移动通信技术以GSM为主，它是数字制式的，除了可以进行语音通信以外，还可以收发短信、MMS、无线应用协议等。目前整个行业正在向第三代和第四代移动通信技术迁移。

A mobile phone is a telephone that can make and receive calls over a radio frequency carrier while the user is moving within a telephone service area. The radio frequency link establishes a connection to the switching systems of a mobile phone operator, which provides access to the public switched telephone network (PSTN). Most modern mobile telephone services use a cellular network architecture, and therefore mobile telephones are often also called cellular telephones or cell phones. In addition to telephony, modern mobile phones support a variety of other services, such as text messaging, MMS, email, Internet access, short-range wireless communications (infrared, Bluetooth), business applications, gaming, and photography. Mobile phones which offer these and more general computing capabilities are referred to as smartphones.