According to her spokeswoman, Fox is engaged to her longtime boyfriend, 36-year-old actor Brian Austin Green.
Green proposed to the "Jonah Hex" star at the Four Seasons Hualalai hotel on Big Island in Hawaii on June 1.
The duo began dating in 2004 and were previously engaged, but called off that engagement last February.
Green has an 8-year-old son with actress Vanessa Marcil.