Brandon Marshall -- Lists Insane Florida Mansion ... Got $5 Million?

Chicago Bears star Brandon Marshall is ditching one of his last memories of his days with the Miami Dolphins -- his MASSIVE Florida mansion ... and TMZ Sports has the pics.

The place is like a palace -- an 11,000 square ft. home on 2.5 acres in a private gated community in Southwest Ranches, FL.

It's got 6 bedrooms, 7.5 baths, a full size basketball court, movie theater, game room, office and an area for HORSES!

Asking price -- just a cool $4.899 million.

We spoke with realtor Jodi Macken of Macken Realty who tells us, "Brandon loves this house and has called it home throughout the off-season."

Macken says the property is the perfect home for a pro athlete in the market.