What alter ego did Beyoncé use prominently during the I Am... Sasha Fierce era?

Beyoncé used the alter ego Sasha Fierce during the I Am... Sasha Fierce era.

I Am... Sasha Fierce was Beyoncé’s third studio album, released in November 2008. The double album was divided into two discs: I Am..., which emphasized more personal and ballad-oriented material, and Sasha Fierce, which presented a more assertive stage persona.

Beyoncé described Sasha Fierce as a performance alter ego that allowed her to become more confident and uninhibited onstage. Songs associated with that disc include “Single Ladies (Put a Ring on It),” “Diva,” and “Video Phone.” The project also included “Halo” and “If I Were a Boy,” which are linked more closely to the I Am... side.

The name was later discussed less prominently as Beyoncé’s public artistic identity evolved. It should not be confused with Queen B or Yoncé, which are nicknames or stage-name variations rather than the specific alter ego named in the album title.