Taylor Swift and Travis Kelce won't make their big debut at the Met Gala, because they're passing on soaking up the spotlight at fashion's biggest night ... TMZ has learned.

Sources with direct knowledge tell TMZ ... the Grammy winner and NFL superstar were each issued individual invitations to the Met Gala, but both have RSVP'd "no" to the celeb-packed evening.

We know Taylor has a pretty good reason for skipping the event, which takes place on May 6 -- that's the same week she gets back on the road for her 'Eras' tour with a stop in Paris.

We're told it's unclear why Travis declined the invitation, but it's fair to assume he's ducking it because Taylor won't be there.

Despite the public nature of their relationship, Taylor and Travis have yet to walk the line for photogs at any premieres or events such as the Met.

The closest they came to that scenario was when they attended Madonna's Oscars after-party, but they arrived under the radar for that one.

Still, Taylor and Travis haven't been shy about hitting up high-profile events. They were front and center for Coachella weekend 1, cuddling up during Ice Spice's set and cheering on Taylor's frequent collaborator Jack Antonoff as he performed with his band, Bleachers.

While the pair will be MIA from the Met Gala, the night won't be lacking for A-listers ... this year's co-chairs include Zendaya, Bad Bunny, Chris Hemsworth and Jennifer Lopez.