Snoop Dogg -- Gambles On Steelers ... Pay Me, Bitches!

Snoop Dogg was pretty fired up after the Steelers game this weekend -- not just because his team won, but he also made $500 off a West Coast rapper who bet on the Raiders.

Snoop made the 2-to-1 wager with Mac Shawn 100 -- telling the guy he was SO confident Pittsburgh would stomp the Silver and Black, he agreed to pay Mac Shawn $1,000 on a $500 bet.

The game came down to the wire, but the Steelers won ... and after the game, the two rappers engaged in some super stoney smack talk.

So, what's Snopp gonna do with the victory money? Well, he is on the way to Denver ...