Ρόδος, Rodos, Rhodos, Rhodes, Rodi, Rodes: they’re all names of the same island – and its capital – in different languages. Many believe that the name originates from the Greek word rhodon (ρόδον)1, translated to rose in English, as there are a lot of roses on the island and the rose was the emblem of the god Helios that was particularly worshiped in Rhodes (the Colossus of Rhodos was dedicated to him).
But, in fact, the name of the island has its roots into the ancient Mythology. According to Diodorus Siculus (Library of History 5. 55. 1)2, Rhode was a daughter of the god of the Sea, Poseidon and Halia and wife of the island’s most important god, Helios the sun. She was one of the Haliades, nymphs of the sea, depicted as beautiful maidens, sometimes riding through the sea on the backs of Hippokampoi (fish-tailed horses), Ketea (Sea-monsters) and dolphins. Rhode was identified by the Rhodians with the goddess Athena (or Minerva), and her seven sons with the Kouretes of Krete.
According to other historians of the ancient times, Rhode was a daughter of Helios and Amphitrite, or of Poseidon and Aphrodite, or lastly of Oceanus (Pindar/Olympian vii. 24, Tzetz. ad Lycoph. 923). The legend says that when the gods gathered to distribute among themselves the various countries of the earth, the island of Rhodes was yet covered by the waves of the sea. Helios was absent at the time; and as no one drew a lot for him, he was not to have any share in the distribution of the earth. But at that moment the island of Rhodes rose out of the sea, and with the consent of Zeus he took possession of it, and by the nymph of the isle he then became the father of seven sons. (Pindar/Olympian vii. 100, Ovid/ Metamorphoses iv. 204.)
Resources: Theoi – Greek Mythology
(1) The Latin word rosa derives from the Greek word rhodon and is the source of almost all names of rose in modern European languages.
(2) Diodorus Siculus was a Greek historian (C1st B.C.).