Anna Wintour's Met Gala guest list just took a hit -- Blake Lively and Ryan Reynolds won’t be gracing the red carpet this year, TMZ has learned.

A source close to the couple tells TMZ ... Blake and Ryan are skipping the gala this year -- but before you jump to conclusions, it’s got nothing to do with their legal war against Justin Baldoni, 'cause the decision to pass on the May event was made way before that drama unfolded.

Blake has become iconic over the years when it comes to the Met Gala, with her themed red carpet looks always making a huge impact -- but she and Ryan don’t always show up, and they actually skipped last year, too!

Still, when it’s Met Gala season -- the event is scheduled for May 5 -- you can usually count on them being there more often than not.

If they were to show up this year, Blake and Ryan would definitely steal the spotlight ... just like they did at their latest public appearance at Feb's "SNL 50." Their appearance had everyone buzzing -- some loved how they laughed off the JB drama, but the display also had critics bashing the moment.

Of course, the married couple is currently tangled up in a legal battle with Baldoni over the drama surrounding the movie "It Ends with Us."