Hair she is! Chappell Roan hit NYC looking like a Disney princess straight out of a fever dream -- filming her new music video while rocking a very OTT Rapunzel-inspired 'do.

The scene was pure pop fantasy -- Chappell was spotted lounging on a Manhattan fire escape railing Monday ... with miles of thick crimped red hair cascading over the edge as cameras rolled on her latest music video.

Don’t be fooled -- Chappell’s not out here testing some miracle hair serum or rocking a Rapunzel-grade wig. The fiery tresses were already draped over the railing, and she simply popped out with her real hair, perched perfectly to make it look like those ground-length locks were all hers.

Definitely a genius move when it comes to working smarter, not heavier -- 'cause LBR, dragging all that hair on her scalp would've been a one-way ticket to neck pain.

Still no word on what single this shoot’s for -- but fans are betting it’s for "Subway,” given the not-so-subtle Big Apple vibes.

But one thing's certain -- with her hair down, power up, Chappell’s not waiting on a Prince ... 'cause she clearly is the main event!