Russell Wilson & Ciara -- Surprise Kids At Children's Hospital

Cool move by Russell Wilson and his GF Ciara ... who made a surprise visit to Seattle Children's Hospital last night -- and kids LOVED IT!!!

We're told the NFL's new hot couple spent time talking to several patients, taking pics and signing autographs. One patient even sketched out a pic for Russell ... complete with his trademark eye black.

After the visit, the hospital tweeted at the stars ... saying, "Thank you @DangeRussWilson & @Ciara for a surprise, star-studded evening for our patients. Feeling starstruck."

BTW -- Seattle Children's Hospital has been a celebrity hot spot this year ... with Chris Pratt and Chris Evans visiting the kids right after the Super Bowl.