Listly by Laura Reed
You can find thousands of public domain images on Pexels. The search function allows you to search for various keywords and images of all kinds of topics.
Search Millions Public Domain/CC0 stock images, clip-art, historical photos and more. Commercial use OK. No attribution required. No login required.
The public beta of a new Creative Commons search tool, meant for testing and feedback. For the legacy search tool, please visit search.creativecommons.org.