McDonald’s is going cluckin’ crazy in Sin City … taking over the Las Vegas Sphere with an advertisement for its new Chicken Big Mac — and, reportedly paying a huge tab to do so.

The fast-food franchise is advertising its “winner-winner chicken dinner” new sandwich on the outside of the iconic Sphere in Vegas … with a close-up of the delectable snack turning slowly around the outside of the multi-billion-dollar arena.

Watch the video … that mouth-watering OG Big Mac spins before transforming into its chicken version — visible basically anywhere in Las Vegas, in an effort to get people to rush to their nearest Mickey D’s for a bit of bird.

As we told you … the Chicken Big Mac was released in the United States this week after blowing up in the UK during a limited release — and, clearly the brand feels pretty confident in the sandwich.

The Chicken Big Mac sold out in the UK in 10 days … so, it’s worth the hefty advertising investment to take over the Sphere — which some reports say costs as much as $450K per day to advertise on.

With an advertising budget that big, McDonald’s better hope the gambit pays off … or the whole brand might be looking more clownish than Ronald McDonald.