Elisabetta Dessy was born in Rome, Italy. She is the first of four children born to countess Amalia Acqua and her husband Giorgio Dessy, an Air Force captain.
She was a member of the National swimming team from 1971 to 1976. Dessy competed in the 100 m breaststroke and 100 m freestyle at the 1974 European Aquatics Championships. She was part of the National team during the Latin Swimming Cup in Marseille 1974, Las Palmas 1975 and Acapulco 1976; she also competed in the Five Nations Swimming Championships between 1973 and 1976 in Järfälla, Minsk, Erfurt and Nice.
Elisabetta Dessy was on the 4 × 100 m freestyle relay team that won the gold medal at the Mediterranean Games in 1975 in Algiers, and won the bronze medal in the 100 m freestyle.
As captain of the Italian Swimming team, she took part in the 4 × 100 m mixed relay during the Olympic Games in Montreal in 1976, setting the new Italian record during the semifinals. She was Italian Champion of the 100 m freestyle in 1974, 1975 and 1976, in the 4 × 100 m freestyle relay in 1972 and 1973, and in the mixed relay 4 x 100 m.
