Sean Penn is an American actor, filmmaker, and political activist. He is known for his roles in films such as Mystic River, Milk, and Dead Man Walking, for which he won the Academy Award for Best Actor. Penn has also been involved in politics, advocating for human rights in Haiti and campaigning for progressive social change. He is also a vocal critic of President Donald Trump. Penn's career in Hollywood began in the early 1980s and he has since become one of the most respected actors in the industry.