What alter ego appears in the title of Beyoncé’s 2008 double album?

Sasha Fierce is the alter ego named in Beyoncé’s 2008 double album I Am... Sasha Fierce.

The album was designed as two discs with contrasting moods. “I Am...” focused on ballads and personal material, while “Sasha Fierce” represented a more confident, performance-oriented persona associated with the stage.

The project included “If I Were a Boy,” “Halo,” “Single Ladies (Put a Ring on It),” and “Diva.” It was released internationally in November 2008 and became one of Beyoncé’s most commercially successful albums.

Beyoncé later said that she had retired the Sasha Fierce persona by around 2010, explaining that it had served as a way to separate her public performer identity from her private self. The title is therefore not the name of a separate singer or band.