The Sleeping Beauty villain was last seen alive in the ABC drama's first season, reported Entertainment Weekly.
Emma (Jennifer Morrison) was thought to have slain Maleficent in dragon form during season one's finale, but the character is set to return for a large story arc.
A ghostly form of Maleficent was also briefly seen in season two and later appeared in spin-off 'Once Upon a Time in Wonderland'.
Characters from Disney's 'Frozen' will form part of the upcoming season, with Elsa (Georgina Haig), Anna (Elizabeth Lail), Kristoff (Scott Michael Foster) and Prince Hans (Tyler Jacob Moore).
Bauer van Straten has just wrapped up HBO's 'True Blood', in which she played vampire Pamela Swynford De Beaufort.
'Once Upon a Time' will return to ABC on September 28.