The company believes that those who commented that the planes were filled with cockroaches and insulting passengers could not uphold the standards of customer service.
The airlines are part of Richard Branson's Virgin group. The comments were focusing on the planes that fly out of London's Gatwick airport.
"Virgin Atlantic can confirm that 13 members of its cabin crew will be leaving the company after breaking staff policies due to totally inappropriate behaviour," the airline said in a statement.
"Following a thorough investigation, it was found that all 13 staff participated in a discussion on the networking site Facebook, which brought the company into disrepute and insulted some of our passengers."