An Estrogen Brigade is the common name for online fan clubs of male science fiction actors created by and mostly for women. These brigade names are often preceeded by the name of the actor in question, and are enjoyed by fans across the spectrum, ranging from the fanatical stalker to the casual appreciator, with everything in between.

The brigades are commonly abbreviated using the actor's initials follwed by the letters EB.

A less common variant of the estrogen brigade type of fan club is the Testosterone Brigade, abbreviated as above, but with TB instead.