One minute she's a football player ... the next, Paris Jackson is pom-pomming her face off on her prep school's cheerleading squad ... another sign MJ's daughter is as free a spirit as he was.

Paris -- sporting a short new 'do -- hit the hardwood and rooted on the Buckley School basketball team in L.A. yesterday ... while hamming it up for the cameras.

Click here for pics and a video of Paris cheering