Mike had a full fledge celebration.

Mike Tyson build a full weed-themed resort with hotel, amphitheater and campsites. He grows various strains of marijuana that are sold in dispensaries throughout California and in Las Vegas. Tyson says the operation sells about $500,000 a month in weed products. Mike said it would be a lot more if he didn’t smoke so much himself lol.

The former boxing champ says he and his pals smoke about $40,000 every month at the Tyson Ranch in the Mojave Desert. As guest of his ranch rapper Jim Jones, said in response, “That’s a lot of weed. That’s nonstop, every second weed right there.”

We agree.

The boxing legend is now a full marijuana advocate and entrepreneur -- and to celebrate the biggest weed holiday of the year, he fired up a joint and explained why the day is so important to him.

He views it as "medicine" and raves that it's changed his life for the better

Now, he views 4/20 as an important day -- because it symbolizes the beginning of the "revolution" to de-criminalize weed all over the world.

Tyson revealed his dream celebrity smoking buddy is Bob Marley. Tyson said “I would have LOVED to spark up with Bob Marley”!

We bet Mr. Marley would have totally been down!