Harington, 28, who played Jon Snow, son of Ned Stark, since the show's first part in 2011, was killed off on the fifth season's finale last month.
He was recently photographed at a Wimbledon tennis match in London sporting long locks, reported Aceshowbiz.
Back in January, the actor, who had revealed that he was contractually obligated to keep his hair long for the duration of the show, appeared with shorter hair at the premiere of his movie "Testament of Youth".
Another fan named Tom Feeney wrote, "Jon Snow lives because of Kit Harington's hair."
"This is a recent picture of Kit Harington, notice his hair. He hasn't cut it. JON SNOW LIVES. #GameofThrones," tweeted another fan.