Mennea, who held the 200-metre world record for 17 years, died from an unspecified illness at a hospital in Rome this morning.
A statement published on coni.it read: "Italian sport is in mourning. We are tearful and emotional after Pietro Mennea died in a Roman clinic this morning following a long-term illness.
"The sprinter, who won a gold medal in the 200m at the 1980 Olympic Games in Moscow and defended the world record at that distance for more than 16 years, was born in Barletta on June 28, 1952."
Mennea won the first of his 14 Italian outdoor titles in the 100m and 200m in 1971 before making his Olympic debut in Munich the following year, winning bronze in the 200m final.
The 1974 European Championships saw him claim the 200m gold in Rome but Mennea could only place fourth in the 1976 Olympic Games in Montreal.
His time of 19.72secs at the World University Games in 1979, however, would not be bettered until Michael Johnson clocked 19.32secs during the USA's Olympic trials for the 1996 Games in Atlanta.
Mennea finally collected an Olympic gold medal by beating reigning 200m champion Don Quarrie and 100m champion Allan Wells by 0.02secs at the 1980 Olympic Games in Moscow.
He also returned from Russia with a second Olympic bronze for helping Italy to win the 4x400m relay final.
He briefly retired in 1983 before returning to win 200m bronze at the inaugural World Championships in Helsinki, going on to finish seventh at the 1984 Games in Los Angeles before competing in his fifth and final Games in Seoul four years later, where he failed to qualify for the final.
Having studied political science towards the end of his running career, Mennea began a five-year term as an elected member of the European Parliament in 1999.
CONI president Giovanni Malago has today cancelled a scheduled business trip to Milan to return to Rome and supervise the organisation of Mennea's funeral.
Malago has also called for a moment of silence to be observed at all sporting events taking place in Italy this weekend.