The ''Why Don't You Love Me?' singer featured during a segment promoting her mother Tina's new fashion line.
The show's co-host Hoda Kotb began screaming in shock after realising the true identity of the model.
Beyoncé, who was sporting frizzy hair and a black dress, said: "[My mother] has always been my biggest supporter so I was very excited to do this for her."
She also revealed that she is still working on her "up-tempo" new album, commenting: "Now I'm trying to go take a break and I can't help it, I just have to go into the studio."
