Casino mogul Steve Wynn is putting his Sun Valley, Idaho, homes on the market as he looks to sell a huge swath of his personal real estate for close to $300 million.

Mr. Wynn is listing two adjacent Sun Valley properties for $27 million, after listing a Palm Beach residence for $78.5 million and a New York City penthouse for $90 million. In addition, a $100 million Beverly Hills, Calif., estate he listed last year is still on the market. He sold his Las Vegas, Nev., home for $17.5 million in June, records show.

Mr. Wynn, 80, is taking his chances on the luxury market at a time when it is faltering amid rising interest rates and economic uncertainty. He didn’t respond to a request for comment.