Lange recently hinted that she was "seriously thinking" about coming back to the hit programme because of its "great writing".
When asked in an interview on Bravo's Watch What Happens whether the actress will be back, showrunner Ryan Murphy answered: "Yes!"
Lange, who played the mysterious Constance Langdon on the first season of the hit, recently won Golden Globe and SAG awards for the role. She will be starring as an entirely new character in the next season.
There is no word yet on which other cast members will also be signing on.
American Horror Story returns to FX later this year.
Watch Ryan Murphy discuss Jessica Lange's return to American Horror Story below (US only):