NetBIOS over TCP/IP（缩写为NBT，或是NetBT），一种网络协定，能让旧有使用NetBIOS API的软件，在现代TCP/IP网络上继续运作。

它在1980年代开始发展，目标是针对于小型网络。在当时，许多使用NetBIOS API写成的软件，缺乏可扩展性，无法直接移植到TCP/IP网络上。NetBIOS over TCP/IP的出现，让过去运作在NetBIOS Frames协定之上的机器，能够连接到TCP/IP网络上。

这个协定定义在 RFC 1001 与 RFC 1002 。

NetBIOS over TCP/IP (NBT, or sometimes NetBT) is a networking protocol that allows legacy computer applications relying on the NetBIOS API to be used on modern TCP/IP networks.

NetBIOS was developed in the early 1980s, targeting very small networks (about a dozen computers). Some applications still use NetBIOS, and do not scale well in today's networks of hundreds of computers when NetBIOS is run over NBF. When properly configured, NBT allows those applications to be run on large TCP/IP networks (including the whole Internet, although that is likely to be subject to security problems) without change.