David Letterman is telling Taylor Swift‘s NFL haters to “shut up” about her romance with Travis Kelce — even though he seems a little confused about who her boyfriend is.

The talk show host offered up a passionate defense of Taylor in a new clip he posted to his social media … and yes, it’s a fierce cosign of all things Taylor, whom he calls a bright light in a world full of darkness.

Also … DL hilariously confused TK for Kelsey Grammer — something he continued to mistakenly say, even after being corrected a couple times. Point being … he loves Taylor!

According to David, Tay doesn’t deserve any hate whatsoever … especially if her stadium-packing credentials are anything to go by — but to those who couldn’t care less about her pop culture icon status and don’t want her anywhere near the pitch … he tells ’em to zip it.

David says T&T’s PDA-packed relationship is a lovely, positive, and good thing for both the NFL camp and Taylor’s own. He just wants more unity in the world, not division — and he seems to think Tay-Tay provides that.

ICYMI, Taylor’s been coming out to cheer on the KC Chiefs tight end since September … though she’s been heavily criticized for distracting from the sport by fuming diehard fans.

In fact, Tony Dungy even recently compared her to outside noise affecting the game itself in a Fox News interview — and who can forget Taylor’s viral stare-down with Golden Globes host Jo Koywhen he mocked her NFL appearances during his opening monologue?

Clearly, the whole thing’s a very divisive matter, but David’s saying just let them love and live — adding: “God, bless Taylor Swift and Kelsey Grammar (Travis Kelce).”

Talk about a ringing endorsement, huh?