How many Klingon speakers are there?

Unknown.

The population size of Klingon speakers is yet to be precisely quantified. In an article posted in 1996 on Wired website, the director of the Klingon Language Institute affirms there are only 12 fluent Klingon speakers; still, hundreds of others have basic or intermediate Klingon knowledge. The Klingon language was created by linguist Marc Okrand for the Star Trek series, and was featured on the 2006 Guinness World Records as the fictional language with the highest number of speakers.