Carl Lewis won four gold medals at the 1984 Summer Olympics in Los Angeles.
Lewis won the 100 metres, 200 metres, long jump, and 4 × 100 metres relay. His four victories made him one of the defining stars of the Los Angeles Games and matched the four-gold haul of Romanian gymnast Ecaterina Szabó. Lewis’s performance was especially notable because he won events across both sprinting and field athletics, rather than concentrating in only one discipline.
The 1984 Games took place from July 28 to August 12 and were held in the United States. The Soviet Union and several other Eastern Bloc countries boycotted the Olympics, which affected the competitive landscape in some events, but Lewis still had to defeat strong international opposition in his races and the long jump.
Lewis later won additional Olympic gold medals at the 1988, 1992, and 1996 Games. He ultimately collected nine Olympic gold medals in total. That larger career figure is the most likely source of confusion: the question asks only about the 1984 Olympics, when his total was four.