Fast Ethernet is a collective term for a number of Ethernet standards that carry traffic at the nominal rate of 100 Mbit/s, against the original Ethernet speed of 10 Mbit/s.

Fast Ethernet is no longer the fastest form of Ethernet: Gigabit Ethernet and the new 10 Gigabit Ethernet standards are 10 and 100 times faster, respectively.

See also

100BASE-T, 100BASE-TX, 100BASE-FX and IEEE 802.3