Kim Kardashian Wears Wedding Dress, Joins Kanye at 'Donda' Event

Kim Kardashian did more than just support her former hubby from the audience, she got involved in the action too, wearing a wedding dress!!!

Kanye's performance at Soldier Field in Chicago Thursday night featured plenty of guest appearances -- including some head-scratchers like DaBaby and Marilyn Manson -- but the audience went most crazy when Kim showed up outside the mockup of Kanye's childhood home in the dress.

Kim stepped out in a stunning Balenciaga Couture wedding dress during the song "No Child Left Behind," the final song of the night.

Now, our sources with direct knowledge have told us for weeks the two are NOT back together ... but they're forever family. Kim and Kanye have always supported the other's endeavors and will continue to do that in the future, whether it be a collaborative effort or not.

Our sources say Kim was happy to do it for Kanye and the event, which was so important to him.

By the way, the wedding gown moment came just minutes after Kanye -- or a likely stunt-double -- lit themselves on fire and walked around the house ... talk about a turn of events!

As we reported ... the event in Chicago marks the third "Donda" event, but the official product hasn't dropped yet.