Which Beyoncé album introduced the character name Sasha Fierce?

I Am... Sasha Fierce introduced the character name Sasha Fierce.

Released in 2008, the album was designed as a double record. The “I Am...” disc focused on more personal and vulnerable songs, while the “Sasha Fierce” disc emphasized energetic performance and a confident stage persona.

Beyoncé described Sasha Fierce as an alter ego that emerged when she performed. The concept helped distinguish private emotion from the bold, highly controlled presence associated with her concerts and music videos.

The album produced major singles including “If I Were a Boy,” “Halo,” “Single Ladies (Put a Ring on It),” and “Diva.” “Single Ladies” became especially influential because of its choreography and black-and-white video. Sasha Fierce is an album-era persona, not Beyoncé’s legal name or a separate recording artist.