Born in Egypt, Kasdaglis moved to England as a child, where his father ran a cotton trade. Xenophon and his brother Dionysios Kasdaglis - also tennis players - finally took over Emmanuel Casdagli & Sons from their father. He started playing tennis while studying in England and France. In 1898 he won the French championships in doubles, the forerunner of the French Open, alongside Marcel Vacherot .
Back in England he won the double competition of the Northern English Championships three times , in the singles he was twice in the finals. He started at the Wimbledon Championships in 1907 and 1922 . His best result was reaching the semi-finals in 1907 . In 1908 and 1909 he won mixed doubles. At the time, the competition was not yet an official part of the tournament. The greatest success of Kasdaglis was the medals at the Olympic Intermediate Games in Athens in 1906 . In tennis doubles , which he played with his compatriot Ioannis Ballis , he was only defeated in the final by the French Max Décugis and Maurice Germot and won silver. In mixed it was enough to win the bronze medal together with the Greek Aspasia Matsa .
Personal
Kasdaglis married Lucia Agelastos in 1908 and had two children with her. He died in 1943 after complications from a minor operation. He was also given British citizenship before 1901.