Lewis Hamilton is still considering making the jump from Formula One to NASCAR ... telling TMZ Sports he ain't ruling it out.
The 4-time F1 World Champ first expressed interest in NASCAR back in 2015 ... saying he'd like to take a stab at the Daytona 500.
That hasn't happened yet -- but when we saw Hamilton at LAX on Tuesday, he told us he isn't shutting the door on NASCAR.
"Maybe ... maybe one day," Hamilton said.
We also asked why he thinks F1 hasn't taken off in the U.S. like it has in the rest of the world -- and the 33-year-old superstar broke it down for us.