Having access to icons that you can use for your projects can be a little hard at times. You can use the website listed below to help you with your search and find the icons that best suits you for your next design project.

the Noun Project
the Noun project has a vast collection of icons that you can use for your projects. You can use their add-ins with Adobe and Microsoft software, as well as with other apps. Free and Pro version available.

Ionicons
Ionicons offers a large collection of icons that are opensource and MIT licenced. Built by the Ionic Framework team.

Simple Icons
1000+ SVG icons for popular brands.

Icons8
Over 100,000 free icons ready to be used. Icons available in various formats and size and styles.
Requires attribution if you are a free user.

Animaticons
Animated icon gifs that save you a lot of space if you are a web designer who wants to implement some motion into your work. Some of the animations are free but some require a small payment.

UX Wing
UX Wing offers a wide range of icons that you can use for personal or commercial projects. Icons are available in PNG or SVG format.

Font Awesome
One of the well-known places where you can get icons for your projects. Font Awesome offers free and pro versions, but the free plan should be enough for most designers as it has over 1500 icons.