What name did Beyoncé use for her stage alter ego during the 2000s?

Beyoncé used the name Sasha Fierce for her stage alter ego during the 2000s.

I Am... Sasha Fierce, released in 2008, presented two connected sides of Beyoncé's artistic persona. The “I Am...” disc explored more vulnerable and intimate material, while “Sasha Fierce” emphasized bold performance energy and club-oriented songs.

Beyoncé described Sasha Fierce as a persona that emerged when she performed, helping her separate the confidence of the stage from her private self. The album produced major hits including “If I Were a Boy,” “Single Ladies (Put a Ring on It),” and “Halo.”

The name is not the same as Beyoncé's later nicknames, such as Queen Bey or Yoncé. It is specifically associated with the 2008 album and the performance identity she discussed in interviews at the time. Beyoncé later said she had retired Sasha Fierce as a separate persona.