软件电话（Softphone）是能够在各式电脑平台（如PDA）在互联网协议基础上使用的语音会话（VoIP），可以用声卡连接Handset, 或是USB Phone。

软件电话最近才开始普及，原因是功能上的突破。早期的软件电话只能在电脑上互传音效, 今日已经可以是PC对电话机或电话机对PC互传音效。且音效品质有极大的改进。

Skype, Google Talk, 和 Vonage 是目前主要的网络电话供应商, 他们提供自家的软件让用户下载并安装到电脑上。

目前软件电话已拥有许多标准电话的特色（DND, Mute, DTMF, Flash, Hold, Transfer 等）还有许多新的特色 Presence, Video, Wideband Audio 还有更多。编解码为 G.711, GSM 以及 iLBC.

A softphone is a software program for making telephone calls over the Internet using a general purpose computer, rather than using dedicated hardware. The softphone can also be installed on a piece of equipment such as a workstation, portable computer, tablet or even a cellphone and allows the user to place and receive calls without requiring an actual telephone set. Often a softphone is designed to behave like a traditional telephone, sometimes appearing as an image of a phone, with a display panel and buttons with which the user can interact. A softphone is usually used with a headset connected to the sound card of the PC, or with a USB phone.