Severed Heads is an Australian electronic music group based and founded in Sydney in 1979 (see 1979 in music) as Mr. and Mrs. No Smoking Sign. The original members were Richard Fielding and Andrew Wright, and were soon joined by Tom Ellard. Fielding and Wright eventually left the group, leaving Ellard as a singular talent, the sole continuing member of the group. A variety of people played in Severed Heads, including Garry Bradbury, Paul Deering, and Stephen Jones, but over time the group devolved to Tom Ellard.

In early 2008 Ellard announced that Severed Heads was now defunct and that no further creative output would be released under this name. However, in November 2009, it was announced that Severed Heads would be performing a 30th anniversary show on January 14, 2010 as part of the annual Sydney Festival. It's unclear if this will be a one-off event, or if the Severed Heads name will be revived for the longer term.

In January 2011, it was announced that Severed Heads would be supporting Gary Numan in a tour celebrating the 30th anniversary of the album The Pleasure Principle the following May.

The band's name change to Severed Heads, from the aforementioned Mr. & Mrs. No Smoking Sign, was meant, in part, as a joke. Tom Ellard: “...We were called Mr. & Mrs. No Smoking Sign, because that was really ugly. Then, we wanted to fool people that we were Industrial and it worked. Severed Heads was a really dumb name, so that’s what stuck. Forever. I hate it by the way.”

Early Severed Heads music was characterised by the use of tape loops, noisy arrangements of synthesizers and other dissonant sound sources, putting Severed Heads in the general category of industrial music. After several releases in that vein, Severed Heads began incorporating various popular music tropes, such as a consistent 4/4 rhythm, strong melodic lines, resolving chord arrangements and Ellard's thin but gently eerie vocals and elliptical, poetic lyrics. This move was underscored by the incorporation of mimetic devices, such as drum machines and bass synthesizers. The result was a striking hybrid of the avant-garde industrial and pop.

Severed Heads were signed to Nettwerk records in North America, and Volition Records in Australia, and charted in 1984 with the song "Dead Eyes Opened". This deal led to a world tour, which was as much a multimedia event, thanks to the video synthesizers of Stephen Jones. They also charted in the United States in the late 1980s with a 12-inch single of "Greater Reward" (from the album Rotund For Success) assisted by several remixes by Sydney-based producer Robert Racic. Racic, who produced album tracks and various singles on and off through the late 1980s and early 1990s and became integral to the Severed Heads sound of that period.

Nettwerk severed its relations with Ellard in the early 1990s, leaving the band adrift in the marketplace. Ellard sought out another label for his next release, Gigapus, in 1995, which was released on Volition in Australia and Decibel Records elsewhere. Around this time, the band had a major Australian hit with a remixed version of "Dead Eyes Opened". Both Volition and Decibel soon folded, and once again, Severed Heads were unaligned with the traditional music industry, and didn't fully own the rights to their music. This changed in 1998, when Sony Music sold Ellard the rights back for a nominal fee.

With his music back in his hands and fully independent, Ellard took this on as a challenge and began developing an independent music system, which is entirely Internet based, at (the link is below). During the early 2000s, Tom Ellard blazed an independent path for his art and developed several innovative products, such as the Sevcom Music Server, a subscription based ambient music distribution system.

Ellard has worked on a side project, Coklacoma, which released a few CDs in the late 1990s. By 2004, he was heavily involved with developing video but increasingly felt that the Severed Heads label was a thing of the past, and in 2008 opted to jettison the name. Ellard also worked extensively during the 1990s with other Sydney based electronic musicians and groups such as Paul Mac (of Itch-E and Scratch-E) and Boxcar, former alumni of the now-defunct Volition label, as well as The Lab.