Media 10, the organizers of Destination Star Trek London wanted to break the Guinness World Record for “The Largest Gathering of People Dressed as Star Trek Characters,” and it’s now been officially confirmed by Guinness World Records. It took place on October 20, 2012, at the ExCel London. That’s when and where 1,063 gathered together in costume, besting the previous record 1,040, set at a Trek convention in Las Vegas two years ago.
I will say I was one of those 1,063 people all gathered in the talks hall of which the 5 captains gave their talks together over the 3 days.  It was a lot of fun and also great to be part of a world record achievement.

From the Destination Star Trek London website
Today Guinness World Records confirmed that Media 10, the organisers of Destination Star Trek London officially hold the world record for ‘Most People Dressed as Characters from Star Trek’ – breaking the previous record of 1040, by 23 people to claim the new record of 1063.
Destination Star Trek London organisers would like to thank all of their visitors who took part and helped us to achieve such a great feat for a first event!
Sign up to the DSTL newsletter to be the first to know when details are released about our next event.
Source Destination Star Trek London, Star