Creative Commons Search
CC Search, the Creative Commons search tool, lets you pick a range of general sources and media types which you want to search for. The tool also lets you lets you pick a number of image sources you want to search across including Flickr, Fotopedia, Google Images, Open Clip Art Library, Wikimedia Commons and Pixabay. The CC Search tool automatically filters your search to find Creative Commons licensed resources that you can share, use, and remix.
The site warns it is not a search engine, but rather offers convenient access to search services provided by other independent organizations.