Russell Wilson and Ciara are thiiiis close to being man and wife -- they're getting married in a ceremony in England in just a few hours ... and are making sure NO ONE leaks any photos.
Our sources tell us ... the couple is set to swap "I Dos" at a castle in front of roughly 100 of their closest friends and family members.
We're told all guests will be asked to fork over their cell phones -- so no one can Snapchat, Instagram, Twitter, Tumblr, Facebook, Pinterest, Periscope or MySpace the event.