O.J. Mayo is close to losing his massive, million dollar mansion in Milwaukee ... 'cause the bank claims the ex-NBA star hasn't made a payment in 10 months ... TMZ Sports has learned.
Here's what we know ... O.J. bought a $1.8 million home in Wisconsin after inking a 3-year, $24 million deal with the Bucks in 2013. At the time, Mayo took out a loan for $1.26 million to help pay for the crib.
The place is SICK -- 9,200 square feet with 5 bedrooms, 4.5 baths, home theater and private gym.