Learned to read at age 2. At the age of 8, she became the youngest person to be nominated for a Screen Actors Guild Award, for her supporting performance in I Am Sam (2001). When she received the Best Young Actor/Actress award from the Broadcast Film Critics Association for her performance in I Am Sam (2001), she was too short to reach the microphone to give her acceptance speech. Presenter Orlando Bloom held her up to the mike for the duration of her speech, which turned out to be quite long.

She began her acting career at 5 when she was picked for a Tide commercial. Older sister of Elle Fanning. Her father named her Dakota, her mother named her Hannah. She then was named Hannah Dakota Fanning. Dakota is one of 14 grandchildren.