Femme fatale, meaning "an attractive and dangerous woman", is a French expression which has become part of the English language roughly since the beginning of the 20th century. Is there another English word or idiomatic expression which conveys the same meaning?
Consider vamp and maneater.
vamp: a seductive woman who uses her sensuality to exploit men; femme fatale
A maneater is the female equivalent of a player. An irresistible woman who chews and spits out men after using them for some sort of gain -- be it sexual, financial, or psychological.
maneater: Slang. femme fatale
Alternately, mantrap might also fit for what you're looking for.
mantrap: Slang. a woman considered dangerously seductive and scheming; femme fatale
You could use the word siren, based on Greek mythology. The Sirens were beautiful women who lured sailors into danger.
Lots of words and expressions in foreign languages have no direct equivalent in English, and none have been devised, simply because it is easier to use the non-English. The foreign phrase conveys an established meaning, which any attempt at translation might lose.
See Oxford Dictionary of foreign phrases http://www.oxforddictionaries.com/words/foreign-words-and-phrases.
It translates femme fatale roughly as 'seductive woman', or 'disastrous woman'.
It is usual when using such expressions to put them in italics.
a woman who seduces, esp. one who seduces a man sexually
You could also use Honeypot or Honeytrap.
I believe vamp, a shorten form of vampire used exclusively to describe females is perhaps the closest word that is I believe considered anglicized. Though its usage is fairly rare outside novels and movies, so I don't know how the general populace would recognize it.
Sharon Stone - might be a better choice, but not quite idiomatic, for a younger pop-culture obsessed audience.
Explanation: The movie Basic Instinct.
Or perhaps Nikita.