The Grammy-winning singer posted a black-and-white photo of herself Monday to her Instagram account, revealing her round belly while also singing with headphones covering her ears.
Morissette captioned the photo with, "so much NEWness."
Her representative confirmed the pregnancy to The Associated Press.
The 44-year-old Canadian singer has two kids: her son Ever Imre is 8 and her daughter Onyx Solace turns 3 in June.
Her hits include "Ironic," ''You Oughta Know," ''Thank U" and "Hands Clean."