The MLB's Field Of Dreams replica officially has Ray Kinsella's stamp of approval ... 'cause Kevin Costner visited it this week and GUSHED over the ballpark, calling it "perfect."
Costner -- who played Kinsella in the 1989 classic baseball movie -- got a tour of the Dyersville, Iowa field just before the Yanks and the White Sox play there Thursday night, and his reaction was awesome.
The 66-year-old walked through the bleachers and stepped on the infield grass ... and was astonished, looking around in bewilderment at how the MLB made the fictional field come to life for an actual game.
"Wow," Costner said. "Feels perfect. Every bit of it."
Of course, the endorsement is big for the MLB ... 'cause if anyone knows what the Field of Dreams is supposed to look like, it's Costner.
The actor absolutely crushed the role as Kinsella more than 3 decades ago ... helping make the movie and the line "If you build it, he will come" a piece of American history.
As for baseball players ... they're loving the idea of the park and the game too -- with Alex Rodriguez and David Ortiz fawning over it all on their visit there this week.
If you weren't aware, the game starts at 4:15 PM PT on Fox ... heads up, "Shoeless" Joe Jackson.