Prince Harry, Meghan Markle, Oprah Winfrey and Ellen DeGeneres all dropped into Kevin Costner's charity event for first responders in California ... proving Hollywood Royalty is very much alive and well.
The A-List celebs descended on the "One805 Live" event at Kevin's Oceanside estate in Santa Barbara Friday to honor local cops and firefighters for their service, particularly during January's horrible storm that caused evacuations in Montecito.
Everyone was in great spirits as Kevin and Oprah delivered speeches about the first responders who proudly stood next to them onstage.
Harry and Meghan also walked out onstage as they were introduced as special guests. At one point, Harry gave an honorary award to Kevin before the Oscar-winning actor launched into his address.
Maroon 5 capped things off with their high-energy performance in front of a packed crowd.
Other notable guests for the $12,000 per-table fundraiser included Kate Perry's parents.
TMZ broke the story, Kevin won big this week after his estranged wife, Christine Baumgartner, agreed to settle their divorce. She's getting $63k a month in child support but would have received $12k more than had if she had settled early on.