There is with little doubt a link between Apollyon and Apollo. Let me elaborate:
The name Apollyon is a Greek play on words for "Apollo" (Apollon in Greek) and "Destroyer." Revelation 9:11 reads, “They had as king over them the angel of the Abyss, whose name in Hebrew is Abaddon and in Greek is Apollyon (that is, Destroyer).” Abaddon means “destruction or ruin” which is “apoleia” in Greek. Though Abaddon means “destruction or ruin” it is truly the place of destruction or ruin which in Greek is Hades or bussos or abussos (Abyss). Why does John call the angel of the Abyss the name for “destruction” or “the place of destruction” in Hebrew but then use the Greek word “Apollyon” meaning “destroyer” which is not an exact Greek translation of the Hebrew Abaddon? John appears to call the angel of the Abyss “Apollyon” rather than using more exact Greek translations of Abaddon like “apoleia,” Hades, “bussos” or “abussos” because of the similarity between the words “destroyer” (Apollyon) and Apollo (Apollon) in Greek. In other words, this word selection appears to be a word play for “Apollo” (Apollon) and “Destroyer” (Apollyon).
The fact that Apollyon is used to intentionally call to mind the god Apollo is hinted at throughout Revelation 9. The Anchor Bible Dictionary says the following concerning the link between Apollyon and Apollo:
In one manuscript, instead of Apollyon the text reads "Apollo," the Greek god of death and pestilence [or plague like the plague of locusts mentioned in Revelation 9] . . . . Apollyon is no doubt the correct reading. But the name Apollo (Gk Apollon) was often linked in ancient Greek writings with the verb apollymi or apollyo, "destroy." From this time of Grotius, "Apollyon" has often been taken here to be a play on the name Apollo. The LOCUST was an emblem of this god[.]” [Emphasis mine.]
Concerning this perceived link between Apollyon and Apollo, Isbon Beckworth writes, “Some (Boss, Holtzm.-Bauer, al.) find in the name Apollyon an indirect allusion also to the god Apollo, one of whose symbols was the locust and to whom plagues and destruction were in some cases attributed (see Rosher, Lex. d. Griech. N. Rom. Mythol. s.v.)[.] The use of the name Apollyon is meant to call attention to this agent’s identification with the Greek God Apollo (hence the plague and locust imagery as well as implicit references to “destroy” in Revelation 9) and his active role as the “destroyer” of Jerusalem. So who could this be, and why is this figure called the “Destroyer” in Greek so as to imply a link to Apollo?
The earthly reflection of Apollyon is Vespasian’s son Titus, the commander of the Legio XV Apollinaris (Fifteenth Apollonian Legion). Initially the commander of the Fifteenth Legion, Titus then went on to succeed his father as general over all the Roman legions during the Jewish War after his father had become Caesar, a title also bestowed on Titus at his father’s coronation. As Caesar, Titus was entitled to worship as a god in the imperial cult, and like Apollo, the son of Zeus, could also be labeled the Son of God--a perfect title for the beast.
At the start of the Jewish War, Titus was the general of the Fifteenth Legion. With Apollo as its patron, the Fifteenth Legion was suitably nicknamed Apollinaris, a name meaning “devoted to Apollo.” The Fifteenth Legion would always carry an emblem of Apollo or one of his holy animals wherever it went. Not surprisingly, the locust was one of Apollo’s holy animals. Now it is easy to see why the author of Revelation chose locusts to symbolize the soldiers of the Roman army following the precedence set in Joel. So “devoted to Titus” was his army that at the taking of the Jewish temple, they unanimously declared him emperor of Rome in fulfillment of v. 11 in which Apollyon is said to have been “king over them.”
This play on words for "Apollo"--the god of death and plague--and "Destroyer" in the name Apollyon perfectly describes the man directly responsible for the remaining plagues of Revelation who was the “destroyer” of Jerusalem. And who coincidentally besieged the city FOR EXACTLY 5 MONTHS just as stated in Rev 9:10!