Feather Icons - Simply beautiful open source icons
Nucleo - Commercial vector icons and accompanying apps to manage and customize them.
IconStore - Free icon packs by first-class designers
The Noun Project - Creating, Sharing and Celebrating the World's Visual Language
Fluent Icons by Icons8 - Colorful and stylish icons for your projects
Streamline icons - The world’s largest icon pack library - 100k icons and illustrations.