Charlie Reynolds is the Starfleet captain of the USS Centaur and an old friend of Benjamin Sisko, who unknowingly attacks Sisko's captured Jem'Hadar fighter early in the Dominion War.
Captain Reynolds is heard but not seen in the sixth-season opener A Time to Stand. He commands the USS Centaur, a small Starfleet ship operating near the front in the first months of the Dominion War.
When Sisko and his crew take a captured Jem'Hadar fighter into Dominion space to destroy a ketracel-white facility, the Centaur spots what looks like a lone enemy ship and attacks. Sisko recognises the vessel and its captain at once, but cannot answer without giving the mission away, and has to run and then fire carefully on his friend's weapons.
The chase ends when real Jem'Hadar ships appear and Reynolds breaks off. Sisko remarks that Charlie never gives up easily, and hopes he gets home.