宽带(英语：Broadband)在基本电子和电子通信上，是描述电子线路能够同时处理较宽的频率范围。宽带是一种相对的描述方式，频带的范围愈大，也就是带宽愈高时，能够发送的数据也相对增加。譬如说在无线电通信上，频率范围比较窄的讯只能发送摩尔斯电码，发送高品质的音乐就需要较大的带宽。电视天线的宽带代表能够接收数量较多的频道。在数据发送方面，同样是以电话线作为信号传递的介质，目前光纤电缆则愈来愈普及，调制解调器只能够每秒钟发送64Kbps的数据，宽带的ADSL和光纤Modem能够提供更高的发送速率。

In telecommunications, broadband is a wide bandwidth data transmission with an ability to simultaneously transport multiple signals and traffic types. The medium can be coaxial cable, optical fiber, radio or twisted pair.

In the context of Internet access broadband is used much more loosely to mean any high-speed Internet access that is always on and faster than traditional dial-up access.