The couple have called time on their relationship after nine months together, according to website Us Weekly.
`Moneyball` star Jonah, 28, is said to have been close to Ali, 24 - who`s father is actor Dustin Hoffman - for some time before they started dating, and even went to the same school, Crossroads High School in Santa Monica, although they were in different years.
Jonah has always been quiet about his relationship with Ali, telling radio DJ Howard Stern in March: "I`m not gonna talk about relationships. This is crazy."
However, when pushed, he added: "She`s f***ing incredible, she`s the greatest person I know. I`m happy." The couple`s union had been rumoured since January this year, shortly after Jonah came back from holidaying with the Hoffman family.
Dustin also had a hand in Jonah`s career, spotting him while he was still in high school and helping him land his first role in `I Heart Huckabees`.
Jonah has previously talked about how close he is to Dustin, saying: "Dustin is the one who encouraged me to be an actor. I knew him through his kids. They went to college with me and high school."
Before dating Ali, Jonah dated his high school girlfriend Jordan Klein for several years, but they broke up in October 2011.