Charles O'Rear is an American photographer. His image Bliss is the default desktop wallpaper of Microsoft's Windows XP operating system. O'Rear started his career with the daily newspapers Emporia Gazette, The Kansas City Star, and Los Angeles Times; worked for National Geographic magazine; and was part of the Environmental Protection Agency's DOCUMERICA project. He began photographing winemaking in 1978.

Bliss, originally titled Bucolic Green Hills, is the default wallpaper of Microsoft's Windows XP operating system. It is an unedited photograph of a green hill and blue sky with white clouds in the Los Carneros American Viticultural Area of Wine Country, California. Charles O'Rear took the photo in January 1996 and Microsoft bought the rights in 2000. It is estimated that billions of people have seen the picture, possibly making it the most viewed photograph in history.