Zach Warner was a male Human and a Starfleet Vice Admiral in the 2370s.

In 2354, Warner lead a Starfleet crew, including Benjamin Sisko to Theta IV-Z. An incident happened that lead to the mission being "botched" although Warner's involvement in it was not well known. He would have a good career after and had risen to the rank of Vice Admiral by 2374. Warner was one of the top ranking Admirals leading Starfleet during the Dominion War.

Soon after the disastrous Battle of Tyra, Captain Sisko, despairing at how poorly the Federation was combating the Dominion, went to see Warner. Sisko called in a favor from Warner citing how long he had kept the secret at what really happened at Theta IV-Z. Sisko wanted to get a position advising the Admiralty on how to successfully fight the Dominion. Warner agreed, although he warned Sisko to not mention his involvement in Sisko's promotion. (DS9 novelization: Call to Arms...)