The couple of three years parted in July after Stewart, 22, publicly admitted she cheated on Pattinson, 26, with her married 41-year-old "Snow White and the Huntsman" director, Rupert Sanders.
"They are living together and have reconciled," an insider said of Stewart and Pattinson.
UsMagazine.com reported the move came after the pair "had a dramatic makeup."
The couple star in the "Twilight" vampire romance film franchise.
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