Do Galaxy S8 and S8 Plus cases and covers work on the Galaxy S9 and S9+?

Nope. They won’t. As we told you earlier, the dimensions of the Galaxy S9 and S9+ are a tad different from the Galaxy S8 and S8+ respectively. So, they won’t fit in properly. So, if you are looking to buy a shiny Galaxy S9 or S9 Plus for yourself, make sure you get yourself new cases too.