American actor best known for his role as Ari Gold on the HBO series Entourage, which earned him three Emmy Awards as well as a Golden Globe. He has also played prominent roles in such films as Old School, The Family Man, and Spy Kids: All the Time in the World.
He trained at Piven Theatre Workshop, an organization founded by his parents, alongside John Cusack.
In 2013, he began playing the title character in the British TV drama series Mr. Selfridge.
His parents are named Byrne and Joyce. His sister, Shira Piven, is a director.
He co-starred with Adrian Grenier on the hit HBO series Entourage.