w3dev

Seamlessly integrates the fancyBox 3 script into your WordPress installation: Upload, activate, and you’re done. Additional configuration is optional.
You can easily customize almost anything you can think about fancyBox lightbox. By default, the plugin will use jQuery to apply fancyBox to ANY thumbnails that link directly to an image. It will also automatically convert WordPress image galleries into fancyBox galleries.
For Inline content linking 
– Create a link to any hidden or visible div with an ID attribate, and the plugin will transform the link and enable it for fancyBox usage. 
– Note: this may cause a conflict if your page or website is using a smooth scrolling function to jump between page sections!
In upcoming versions, additional functionality for ajax calls and iframe data will be implemented.

fancyBox 3 for WordPress

Seamlessly integrates the fancyBox 3 script into your WordPress installation: Upload, activate, and you're done. Additional configuration is opti …

Ajay Maurya

Flying Cursor

WP Post Gallery Fancybox is a WordPress plugin that converts the default WordPress Media Gallery into a Fancybox Gallery.
Just add the gallery shortcode to display the thumbnails in your posts/pages and this plugin does the rest, It makes your gallery to appear as a Fancybox Gallery.
<a href="https://fancyapps.com/fancybox/3/#images-1" rel="nofollow ugc">Demo of Fancybox</a>
Touch Enabled and Fully Responsive Lightbox. 
Slideshow and Full screen options available.
<h3>Features</h3>
<ul>
<li>Mobile optimized</li>
<li>Responsive, touch-enabled and customizable.</li>
<li>Multiple instances (Add Multiple Galleries on a single page)</li>
</ul>
<h3>Credits</h3>
The FancyBox jQuery plugin is written by Janis Skarnelis: 
https://fancyapps.com/fancybox/3/

WP Post Gallery Fancybox

WP Post Gallery Fancybox is a WordPress plugin that converts the default WordPress Media Gallery into a Fancybox Gallery.

fancyBox 3 for WordPress vs WP Post Gallery Fancybox