Thomas Karlovich Leyus is a Soviet tennis player from the Republic of Estonia, a master of sports of the USSR. He was born on August 28 in 1941 in Tallinn, in an intelligent family, where he studied music from early childhood. He has been playing tennis since he was ten years old, made his debut at the Estonian SSR Championship in 1957. Beautiful technique and tactical setting of the game could compensate Thomas for his weak physical condition. In the same year he received the title of Master of Sports of the USSR. The very next year, Leyus wins the Estonian SSR championship.

In 1959, Thomas became the first Soviet tennis player to win at Wimbledon, albeit at a junior level. In 1960, he tried himself on the adult Wimbledon, but flew out on the third round. In 1962, at the US Championship he reached only the second round. But two years later he went to the finals of the London Royal Club tournament. A year later, he reached only a quarter of the final part at the French Open, because he became a victim of political games of the Soviet government.
In 1969, in the singles at the Australian Championship, he reached the third round, and in the doubles he got into the quarterfinals. The same year he became a doubles finalist at the New Zealand Auckland tournament. In 1965, Thomas won three silver medals at the USSR Universiade, and five years later won the Universiade gold, as well as two more silver medals.
In 1970, he completed his studies at the Tallinn Pedagogical Institute, where he studied as a teacher of physical education. And the following year he became a finalist in the mixed category at the French Open. Three times he was recognized as an athlete of the year in the Estonian SSR.
1974, the life of Thomas Leyus radically changed. Because of jealousy, he strangled his wife, for which he was sentenced to eight years in prison, but served only three. After his release, he began his coaching career in Uzbekistan, Georgia, Germany and Finland. In 1997 he returned to Estonia, represented the national team at the Federation Cup. In 2009, he was honorably added to the Tennis Hall of Fame.
Throughout his tennis career, he became the 23-time champion of the Estonian SSR and the 10-time champion of the USSR, which gives the right to call him the most successful Estonian tennis player.