Billie Eilish is putting her stylish stamp on the NBA -- the singer is giving fans a chance to rock her signature look at games ... by releasing her own team hats!!
TMZ Sports is told the nine-time Grammy winner teamed up with Fanatics and Complex to release some limited-edition Mitchell & Ness lids -- each being decked out in custom Billie Eilish patches to highlight "authenticity, nostalgia and individuality."
The "BIRDS OF A FEATHER" crooner is no stranger to rocking M&N attire -- she loves her throwback jerseys .