Vulcan has taken more than 100,000 of some 325,000 votes cast in the online poll.
A new 20-30km wide moon of Pluto currently known as P4, was discovered in 2011; another of similar size – P5 – was spotted last year.
Star Trek actor William Shatner, who portrayed the Enterprise’s captain James Kirk, had previously called on the vote organisers to add Vulcan and Romulus to the list of names in contention.
The organisers accepted Vulcan, but rejected Romulus. Both Romulus and Remus (the names of twin brothers in the Roman foundation myth) are already in use as names for the moons of the asteroid 87 Silvia.
However, Mr Shatner appeared pleased that Vulcan made the list, tweeting: “I think we are over 100k votes for Vulcan on PlutoRocks.com that’s wonderful!”
Personally, I’d have gone with Tatooine, but that’s just me…