Yes, Robert Kennedy Jr. is related to John F. Kennedy (JFK). Robert Kennedy Jr. is the son of Robert F. Kennedy, who was the younger brother of John F. Kennedy. This makes Robert Kennedy Jr. the nephew of JFK.
Robert F. Kennedy served as the U.S. Attorney General during his brother’s presidency and was a prominent political figure in his own right. The Kennedy family is one of the most well-known political families in the United States, with multiple members having served in various high-profile positions.