Born in Jacksonville, Florida and excelling in both sprinting and football, Hayes first became successful as a sprinter. In 1963, he set the World Record in the 100 yard dash at 9.1, earning for himself the nickname of "fastest man alive".

At the 1964 Summer Olympics, in Tokyo, Hayes had his finest hour as a sprinter. First, he won the 100 m by tying the current World Record in the 100 m. This was followed by a second gold medal in the 4 x 100 m relay, which also produced a new World Record. The relay race was also Hayes' last race as a track and field athlete as he permanently switched to football after it.

At the end of that same year, he signed with the Dallas Cowboys, playing as a wide receiver. His first two seasons were most successful, leading the league both times in receiving touchdowns. In 1966 when the Cowboys played at Washington, Hayes caught 9 passes for 246 yards.

Olympic medal record Men's Athletics Gold 1964 Tokyo 100 metres Gold 1964 Tokyo 4x100m relay Earlier that same season he caught 6 passes for 195 yards against the Giants at the Cotton Bowl. Hayes speed forced other teams to develop the zone defense since no single player could keep up with him. By spreading the defense out in order to contain Hayes, it allowed the Cowboys running game, with players like Don Perkins, Calvin Hill, Walt Garrison and Duane Thomas to flourish. Hayes returned punts for the Cowboys and was the NFL's leading punt returner in 1968 with a 20.8 yards per return average and 2 touchdowns including a 90 yarder against Pittsburgh. He was named to the Pro Bowl twice. Later in his career, as defenses improved playing zone and "bump and run coverage" was developed, Hayes' value as a decoy diminished. In 1971, Hayes' last statistically good season with Dallas, he won the Super Bowl, becoming the only person so far to win both an Olympic gold medal and a Super Bowl ring. Hayes played one season for the San Francisco 49ers, before retiring.

On September 18, 2002, Hayes died in his hometown Jacksonville of kidney failure aged 59, after battling prostate cancer and liver ailments.

Hayes was close to being elected to the Pro Football Hall of Fame in 2004, but was denied the opportunity in the final round of decision making. The decision was marred by controversy, with many claiming that the Hall of Fame Senior Selection Committee had a bias against members of the Dallas Cowboys and other NFL teams. Others believe Hayes' longstanding problems with drug abuse marred his chances. Shortly after the announcement of the new 2004 Hall of Fame members, long-time Sports Illustrated writer Paul Zimmerman resigned from the Selection Committee in protest of the decision to leave Hayes out of the Hall.