In an Instagram post titled "consent II", the American actress writes "I knew my assailant".
The 20-year-old, known for her role in the film Little Miss Sunshine, says in the post: "You are not obligated to have sex with someone that you're in a relationship with.
"Dating is not consent; marriage is not consent."
It's not known who Abigail Breslin is talking about in her post or when the assault happened.
April is sexual assault awareness month in the US.
The actress has received lots of support from fans and other American actors.