Ben Marshall

Integrate <a href="https://daringfireball.net/projects/markdown/" rel="nofollow ugc">Markdown</a> into WordPress comments with the Parse Markdown plugin. A simple, no configuration-required, standards-driven plugin that allows commenters to use Markdown markup in their comments.
For more information on how it works and how to integrate in other plugins or themes, see the <a href="https://www.benmarshall.me/parse-markdown-wordpress-plugin/" rel="nofollow ugc">Parse Markdown documentation</a>.

Parse Markdown

Integrate Markdown into WordPress. Simple, no configuration-required, standards-driven plugin allowing commenters to use Markdown in their comments.

Mark Jaquith

This plugin allows you to compose content in Markdown on a per-item basis. The markdown version is stored separately (in the <code>post_content_filtered</code> column), so you can deactivate this plugin and your posts won’t spew out Markdown, because HTML is stored in the <code>post_content</code>, just like normal. This is also much faster than doing on-the-fly Markdown conversion on every page load. It’s only done once! When you re-edit the post, the markdown version is swapped into the editor for you to edit. If something external updates the post content, you’ll lose the Markdown version.
Note: this plugin assumes you’re using the Classic editor.

Markdown on Save

Allows you to compose content in Markdown on a per-item basis. The markdown version is stored separately, so you can deactivate this plugin any time.

Parse Markdown vs Markdown on Save