In the New Musical Express November 2, 1974, the song's writer Freddie Mercury elucidates on this song: "It's about a high class call girl. I'm trying to say that classy people can be whores as well. That's what the song is about, though I'd prefer people to put their interpretation upon it - to read into it what they like."
Regarding the line, "'Let them eat cake' she says, just like Marie Antoinette": According to legend, Marie Antoinette (the Queen of France) said "Let them eat cake" after hearing how the peasants had no bread to eat. It's more likely that the phrase was uttered by a French philosopher, not Antoinette. (thanks, Brentley - gibbon, NE)
The Marie Antoinette quote has gone down in History as justification for the French Revolution. It demonstrates how out of touch with the common folk the ruling class had become. According to legend, when informed that there was no bread for the people to eat, she replied, oblivious, "then let them eat cake!" It is said, that enraged by this incredibly ignorant response, the people revolted. In the song, it is used to demonstrate at what level this high priced prostitute sells her wares. (thanks, Kraeg Minett - London, Canada)
This was the band's first major breakthrough on the worldwide singles charts, even though it was taken from their third album. (thanks, Tom - Trowbridge, England)
This song was covered by Sum 41 for the 2005 Queen tribute album Killer Queen. (thanks, Rachel - South Point, OH)
In Ben Elton's musical We Will Rock You, Killer Queen is an evil matriarch who controls the music industry. (thanks, Edward Pearce - Ashford, Kent, England)
In the video game Guitar Hero 3, one of the unlockable guitars called the "Card Sharp Special" can have a finish called "Killer Queen." In the description it says: " Something about dynamite and laser beams? what's that all about? and who am I to deny it?", which is a reference to the song lyrics. (thanks, Paul - Los Angeles, CA)
Brian May said in Q magazine March 2008: "This is a perfect pop record and one of Freddie's greatest songs. It's beautifully constructed and it's also got one of the solos I'm most proud of."
He elaborated further on it in the Days of our Lives documentary: "Every slice of that record is pure pop perfection. Little things that visit once and come again, like the little bell in the second verse."
Nevertheless, he was a little reticent at first about releasing it: "I was a little hesitant; I was thinking are we setting ourselves as something very light?" He relates this back to how initially the band were very heavy and rock-orientated, and "Killer Queen" was a major departure from that sound.
Californian Pop Princess Katy Perry named one of her fragrances after this tune. She told Women's Wear Daily the song's lyrics really spoke to her when she was a teenager. "Killer Queen has been in my vocabulary since I was 15," Perry said. "Freddie Mercury painted the lyrics of this woman who I wanted to be. She seemed very powerful, and she captivated a room when she walked in."