A Vorta field supervisor whose Jem'Hadar seize the Defiant in 2374, and whose decision to place a newly bred Alpha Quadrant soldier over a Gamma Quadrant veteran sows discord in the boarding party.
Gelnon appears in One Little Ship, played by Leland Crooke.
In 2374 his forces capture the Defiant while a miniaturised runabout carrying Dax, O'Brien and Bashir is exploring a subspace anomaly. Gelnon installs Kudak'Etan, one of the new Jem'Hadar bred in the Alpha Quadrant, as First, with the experienced Gamma Quadrant soldier Ixtana'Rax under him as Second. He is candid that the Founders regard the newer breed as an improvement and seems to enjoy the rivalry he has created.
Gelnon then leaves for another engagement, ordering Kudak'Etan to make Sisko's crew restore the warp drive. His departure leaves an overconfident First in charge, which helps Sisko and the tiny runabout retake the ship.