jomol

Simple Font Awesome Icon plugin will give you the Font Awesome Icon option in your post and page. From there you can choose the required icon and hit save. Then use the get_post_meta(‘post ID’, ‘font-awesome-icon’, true); function in the template file and you will get the class name which can be used with i tag.
Please take a look the plugin page for more details: [https://codingdom.wordpress.com/simple-font-awesome-icon/)

Simple Font Awesome Icon

Simple Font Awesome plugin will give you the option for adding Font Awesome icons for your post and pages in the form of a meta box.

deathnfudge

fontawesome

frrrances

mlwilkerson

robmadole

The official way to use Font Awesome Free or Pro icons on your WordPress site, brought to you by the Font Awesome team.
<h4>Features</h4>
Our official plugin makes it easy to add Font Awesome icons to your pages, posts, and templates and includes the following features:
<ul>
<li>Use Pro or Free icons, from the latest release or a specific release.</li>
<li>Use custom icons from your Pro Kits.</li>
<li>Use a Font Awesome Kit to add any of our icons (including the latest Duotone styles and custom icons!), or select the Font Awesome CDN for Version 5 icons only.</li>
<li>Turn on automatic compatibility for Font Awesome Version 4 if you – or your plugins – are still using Version 4 syntax.</li>
<li>Troubleshoot and resolve issues when multiple versions of Font Awesome are loading on your site from other plugins/themes, which can cause unexpected icon display or technical issues.</li>
</ul>
<h3>How to Use</h3>
Install And Enable The Plugin 
(See the Installation tab for details)
How to Add and Style Icons 
Full docs on how to use the plugin and add icons are available on the <a href="https://docs.fontawesome.com/web/use-with/wordpress/add-icons" rel="nofollow ugc">Font Awesome Docs site</a>.
Add Icons in the Block Editor 
Once you’ve set up your plugin, you can add icons as blocks or inline with text.
To add icons as blocks, select the “Font Awesome Icon” block, and then click the “Choose Icon button” to open the Icon Chooser.
To add icons inline, select the Font Awesome option in the format toolbar to open the Icon Chooser. (Note: Inline icons require at least WP 6.3.)
Once you open the Icon Chooser, add icons by:
<ol>
<li>Searching for the icon you want – you can search by icon name, category, or keyword.</li>
<li>Changing the Family and Style using the drop downs if you want an icon in a different style.</li>
<li>When you see the icon you want, clicking it to enter it into the content of your page or post.</li>
</ol>
Note: If you want to search and add Pro icons in the Icon Chooser, make sure you set your plugin to use a Pro Kit.
Add Icons in The Classic Editor 
If you need to add icons in the classic editor, you can <a href="https://fontawesome.com/icons?d=gallery" rel="nofollow ugc">use the icon names in shortcodes or HTML</a>. Add an icon using shortcodes to any text area – just add the name of the icon and a style prefix, where <a href="https://fontawesome.com/how-to-use/on-the-web/referencing-icons/basic-use" rel="nofollow ugc">the prefix is the style of icon</a> you want to use. Note that you don’t need to include the <code>fa-</code> part of the icon name. And if you don’t include any style prefix, the icon will default to the Classic Solid style.
The shortcode for an icon looks like this:
<pre><code>[icon name="stroopwafel"]

[icon name="stroopwafel" prefix="fa-sharp fa-light"]
</code></pre>
You can also use basic HTML with <a href="https://fontawesome.com/how-to-use/on-the-web/referencing-icons/basic-use" rel="nofollow ugc">standard Font Awesome syntax</a>, like this:
<pre><code>
</code></pre>
Using Pro Icons and Features 
To use a Kit to power your icons, <a href="https://fontawesome.com/kits" rel="nofollow ugc">create a Kit on FontAwesome.com</a> and select “Pro icons” in the Kit Settings tab. Then grab your <a href="https://fontawesome.com/account#api-tokens" rel="nofollow ugc">API Token from your Font Awesome Account page</a> and add it to your WordPress plugin settings.
To use the CDN to power your icons, know that you will only be able to use icons from Version 5. To enable Pro icons, add your site’s domain to the list allowed domains on your <a href="https://fontawesome.com/account/cdn" rel="nofollow ugc">Font Awesome CDN Settings page</a> and then use shortcodes or HTML to add the icons into your content.
Troubleshooting with the Plugin 
Font Awesome icons are popular, so lots of themes and plugins also load Font Awesome, and sometimes their version can conflict with yours. So we created a way to help you find and prevent those conflicting versions from affecting your icons: The Conflict Detection Scanner.
If the plugin seems to be set up correctly and your icons still aren’t loading and you’re not sure why, head over to the Troubleshoot tab, which has two parts:
<ul>
<li>Detect Conflicts with Other Versions of Font Awesome – which lets you start the conflict detection scanner to find versions of Font Awesome loading on your site.</li>
<li>Versions of Font Awesome Active on Your Site – which shows the results of the scanner and lets you prevent any conflicting versions from loading other versions of Font Awesome on your site.</li>
</ul>
Get more information about using the scanner for troubleshooting on the <a href="https://docs.fontawesome.com/web/use-with/wordpress/troubleshoot" rel="nofollow ugc">Font Awesome WordPress docs</a>.
<h3>Configuring</h3>
The plugin is set to serve Font Awesome Free icons as a Web Font via the Font Awesome CDN by default. You can change the CDN settings right in the plugin. If you want just the basic Free icons, you probably don’t need to make any changes to the default configuration.
You can get more information about all the available settings and troubleshooting on the <a href="https://docs.fontawesome.com/web/use-with/wordpress" rel="nofollow ugc">Font Awesome WordPress docs</a>.
<h3>Upgrading from Plugin Version 4</h3>
<ul>
<li><code>[icon]</code> shortcodes found in Block Editor content and elsewehre will continue to work as before, 
though new icons added with the Icon Chooser in the Block Editor will be inline SVGs. 
Previously added <code>[icon]</code> shortcodes will not be automatically be converted into the new inline SVG 
format. If you want to convert an <code>[icon]</code> shortcode, delete it and re-add the icon using the Icon Chooser in the Block Editor.</li>
</ul>
<h3>See Also</h3>
The <a href="https://github.com/FortAwesome/wordpress-fontawesome/blob/master/README.md" rel="nofollow ugc">README</a> on GitHub has details for WordPress site owners and developers.
You can get more information about all the available settings and troubleshooting on the <a href="https://docs.fontawesome.com/web/use-with/wordpress" rel="nofollow ugc">Font Awesome WordPress docs</a>.
And there are <a href="https://fortawesome.github.io/wordpress-fontawesome/" rel="nofollow ugc">API docs</a> for developers.

Font Awesome

Update: They refunded me after issues so I revised my rating. I do hope they update their Pro service. Original review below.

I upgraded to Pro because I thought it would speed up my site with their SVGs and the kit. My site load time went from 8 seconds to 20 seconds! If I deactivate the plugin to remove FA my site loads in 3 seconds. I know HTML and CSS so I know what I am doing here.

I have spent 2 months trying to figure out their documentation when I can figure out other programming languages in a couple days. The documentation is vague and not intuitive. Their customer support is equally as bad with one sentence answers that don't answer the question.

I think I might just go without icons to speed up might site. I want my money back!

updated: refunded me

This plugin work great as they did not left the junk behind in the DB on uninstalled.

But I found no option to use the Font Awesome assets (such as CSS+fonts) on my local site without CDN access.

For example that I may have to install the website and then use in the intranet where no external access.

However, there is some errors with WordPress 5.9-RC2-52567, PHP 7.1. It said:

Undefined variable: should_enable_icon_chooser in font-awesome\includes\class-fontawesome.php on line 1623

No local files.

This works perfectly for me where others didn't.

Just works

The Font Awesome plugin makes it easy to stay on top of the latest version that is otherwise hidden away in some assets folder. Block editor support makes it easy to insert icons without having to remember their names. Can't wait for version 6.

Great free icons

For a free product this works quite well and allows users to quickly add font-awesome to their site without messing with custom code.   If they offered a Pro version of this then it would definitely need to be cleaned up to work more easily on the editor side, however for a free piece of software its pretty nice and allows me to more easily integrate font-awesome into my sites.

Thanks!

Excellent Free Product

The official way to use Font Awesome Free or Pro icons on your WordPress site, brought to you by the Font Awesome team.

Simple Font Awesome Icon vs Font Awesome