Born in Paterson, New Jersey, Phil Riker swam for the Lawrenceville School and then the University of North Carolina. He just missed a medal at the Tokyo Olympics, placing fourth in the 200 butterfly. After the 1964 Olympics, Riker won a silver medal in the 200 fly at the 1965 Universiade, adding a gold medal in the 4x100 medley relay. He won the 1966 NCAA title in the 100 fly. Riker was a six-time first-team All-America in the 100 and 200 fly, 4x100 medley relay and 4x200 free relay from 1965-68. He won ACC championships in the 100 and 200 fly in 1966-68 and the 4x100 medley relay in 1967-68. In 2002 Riker was named to the Atlantic Coast Conference 50th Anniversary Team. He later swam in some masters events, representing Palmetto Masters.