|Olympic medal record|
|Competitor for Greece|
|Competitor for a Mixed team|
Dionysios (Greek: Διονύσιος) or Dimitrios(Greek: Δημήτριος) Kasdaglis (Greek: Κάσδαγλης) (10 October 1872 – 1931) was a Greek-Egyptian tennis player. He competed in the 1896 Summer Olympics in Athens and the 1906 Intercalated Games, also in Athens.
Kasdaglis hailed from Egypt and held British citizenship, but according to the official bulletin he participated as a member of the Greek team. He made it to the finals in both the singles and doubles events. In the singles, he defeated Defert of France in the first round, Konstantinos Akratopoulos of Greece in the second, and Momcsilló Tapavicza of Hungary in the semifinals before facing John Pius Boland of Great Britain and Ireland in the final. Boland proved the better player, and Kasdaglis finished second. The medal is credited to Kasdaglis as a Greek by the International Olympic Committee.
For the doubles tournament, Kasdaglis paired with Demetrios Petrokokkinos in a mixed team. They defeated the Greeks Konstantinos Paspatis and Evangelos Rallis in the first round and the British/Australian pair of George S. Robertson and Edwin Flack in the semifinals. In the final, Kasdaglis again faced Boland, this time paired with Friedrich Traun of Germany. Kasdaglis and Petrokokkinos lost that match to give Kasdaglis his second silver medal.
- "Dionysios Kasdaglis Olympic Results". sports-reference.com. Retrieved 2014-01-26.
- The International Olympic Committee's medals database lists this as a mixed team; however, Kasdaglis is himself identified as Greek and Petrokokkinos, whose nationality is not explicitly mentioned by the IOC database, is elsewhere always listed as Greek.