Reports have been circulating in recent years that the star has long been a strong supporter, but the latest photograph has shown the rumours are true.
This photo of the Pulp Fiction star was taken by LA- based Bohs fan Paul Balbirnie, who said the actor told him: "I'm Bohs till I die!"
"I had heard the stories about Samuel L Jackson for some time and I have seen the newspaper articles posted on the Bohs forum," Balbirnie explained.
And the Bohs online forum has been lit up since the photo was uploaded, declaring that there is "proof at last" of the actor's allegiance.
Reports of the star's support emerged in 2007, however they were dismissed as mere rumours due to his LA roots. Now Balbirnie has been elevated to near superstar status among Bohs supporters for seizing the opportunity to get a snap of Jackson and the flag, which he also autographed.
Jackson has made no secret of his appreciation for all things Irish, as he regularly sings the praises of the country during his regular visits here.
He was in the capital in February as guest of honour for Keith Duffy's Valentine's ball, and it is hoped he will be back on our shores this July for a spot of golf, taking part in the prestigious JP McManus Invitational Pro-Am in Limerick.
The veteran actor revealed to the Herald two months ago that he had even challenged Ronan Keating to a game.