The 'Thank U, Next' singer made the announcement Saturday, saying she was officially booked to perform at the 2020 Grammy Awards later this month. She wrote on Instagram, "OFFICIAL: #ArianaGrande will perform at the #GRAMMYs Jan. 26!"

Attached was a promo shot of her with the Grammy logo in the corner, and the words "GRAMMY PERFORMER" emblazoned along her back. So yeah, it's definitely happening.

What's interesting ... Ariana had a big beef last year with the Grammys' longtime executive producer, Ken Ehrlich, who publicly made it seem like Ariana had backed out of last year's show because she was too frazzled and unorganized to pull it together on short notice.

We heard from people connected to the situation that characterization simply wasn't true -- in fact, we were told it was Ken who'd put her in an impossible spot by not allowing her to perform her biggest hit single at the time, "7 Rings," and then later recanting.

By the time Ken realized it'd be better to have AG perform than not, our sources told us he came back to her with the offer to do "7 Rings" when it was too late ... she'd already made up her mind on not doing the show at all, and that's how it ultimately played out. We're told the whole thing left a bad taste in Ariana's mouth, so she just watched from home.

Now, it looks like that's all water under a bridge -- and the reason might be more obvious than you'd think. Earlier this year, Ken announced he's hanging it up after this year's show, so it appears the direction of things is about to change hands -- if it hasn't already.

In Ariana's case ... probably for the better.