diff --git a/Gemfile b/Gemfile
index 1f31549e..08ab18af 100644
--- a/Gemfile
+++ b/Gemfile
@@ -76,7 +76,6 @@ group :jekyll_optional_dependencies do
     gem "classifier-reborn", "~> 2.2.0"
     gem "liquid-c", "~> 3.0"
     gem "pygments.rb", "~> 1.0"
-    gem "rdiscount", "~> 2.0"
     gem "yajl-ruby", "~> 1.3"
   end
 
diff --git a/features/site_configuration.feature b/features/site_configuration.feature
index 4baa36a8..698c59bc 100644
--- a/features/site_configuration.feature
+++ b/features/site_configuration.feature
@@ -65,14 +65,6 @@ Feature: Site configuration
     And the "_site/Rakefile" file should not exist
     And the "_site/README" file should not exist
 
-  Scenario: Use RDiscount for markup
-    Given I have an "index.markdown" page that contains "[Google](https://www.google.com)"
-    And I have a configuration file with "markdown" set to "rdiscount"
-    When I run jekyll build
-    Then I should get a zero exit status
-    And the _site directory should exist
-    And I should see "<a href=\"https://www.google.com\">Google</a>" in "_site/index.html"
-
   Scenario: Use Kramdown for markup
     Given I have an "index.markdown" page that contains "[Google](https://www.google.com)"
     And I have a configuration file with "markdown" set to "kramdown"
diff --git a/lib/jekyll/configuration.rb b/lib/jekyll/configuration.rb
index fb51cd5b..e49eb62b 100644
--- a/lib/jekyll/configuration.rb
+++ b/lib/jekyll/configuration.rb
@@ -66,10 +66,6 @@ module Jekyll
         "strict_variables" => false,
       },
 
-      "rdiscount"           => {
-        "extensions" => [],
-      },
-
       "kramdown"            => {
         "auto_ids"      => true,
         "toc_levels"    => "1..6",
diff --git a/lib/jekyll/converters/markdown.rb b/lib/jekyll/converters/markdown.rb
index 567bc120..3c1c3458 100644
--- a/lib/jekyll/converters/markdown.rb
+++ b/lib/jekyll/converters/markdown.rb
@@ -30,8 +30,7 @@ module Jekyll
       # rubocop:disable Naming/AccessorMethodName
       def get_processor
         case @config["markdown"].downcase
-        when "kramdown"  then return KramdownParser.new(@config)
-        when "rdiscount" then return RDiscountParser.new(@config)
+        when "kramdown" then return KramdownParser.new(@config)
         else
           custom_processor
         end
@@ -43,7 +42,7 @@ module Jekyll
       # are not in safe mode.)
 
       def valid_processors
-        %w(rdiscount kramdown) + third_party_processors
+        %w(kramdown) + third_party_processors
       end
 
       # Public: A list of processors that you provide via plugins.
@@ -52,7 +51,7 @@ module Jekyll
 
       def third_party_processors
         self.class.constants - \
-          %w(KramdownParser RDiscountParser PRIORITIES).map(
+          %w(KramdownParser PRIORITIES).map(
             &:to_sym
           )
       end
diff --git a/lib/jekyll/converters/markdown/rdiscount_parser.rb b/lib/jekyll/converters/markdown/rdiscount_parser.rb
deleted file mode 100644
index 9da177d4..00000000
--- a/lib/jekyll/converters/markdown/rdiscount_parser.rb
+++ /dev/null
@@ -1,37 +0,0 @@
-# frozen_string_literal: true
-
-module Jekyll
-  module Converters
-    class Markdown
-      class RDiscountParser
-        def initialize(config)
-          unless defined?(RDiscount)
-            Jekyll::External.require_with_graceful_fail "rdiscount"
-          end
-          @config = config
-          @rdiscount_extensions = @config["rdiscount"]["extensions"].map(&:to_sym)
-        end
-
-        def convert(content)
-          rd = RDiscount.new(content, *@rdiscount_extensions)
-          html = rd.to_html
-          if @config["rdiscount"]["toc_token"]
-            html = replace_generated_toc(rd, html, @config["rdiscount"]["toc_token"])
-          end
-          html
-        end
-
-        private
-        def replace_generated_toc(rd_instance, html, toc_token)
-          if rd_instance.generate_toc && html.include?(toc_token)
-            utf8_toc = rd_instance.toc_content
-            utf8_toc.force_encoding("utf-8") if utf8_toc.respond_to?(:force_encoding)
-            html.gsub(toc_token, utf8_toc)
-          else
-            html
-          end
-        end
-      end
-    end
-  end
-end
diff --git a/test/helper.rb b/test/helper.rb
index a3cd6568..9e01b7de 100644
--- a/test/helper.rb
+++ b/test/helper.rb
@@ -34,10 +34,6 @@ require_relative "../lib/jekyll.rb"
 
 Jekyll.logger = Logger.new(StringIO.new, :error)
 
-unless jruby?
-  require "rdiscount"
-end
-
 require "kramdown"
 require "shoulda"
 
diff --git a/test/test_rdiscount.rb b/test/test_rdiscount.rb
deleted file mode 100644
index 7116c29a..00000000
--- a/test/test_rdiscount.rb
+++ /dev/null
@@ -1,51 +0,0 @@
-# frozen_string_literal: true
-
-require "helper"
-
-class TestRdiscount < JekyllUnitTest
-  context "rdiscount" do
-    setup do
-      if jruby?
-        then skip(
-          "JRuby does not perform well with CExt, test disabled."
-        )
-      end
-
-      config = {
-        "markdown"  => "rdiscount",
-        "rdiscount" => {
-          "toc_token"  => "{:toc}",
-          "extensions" => %w(smart generate_toc),
-        },
-      }
-
-      @markdown = Converters::Markdown.new config
-    end
-
-    should "pass rdiscount extensions" do
-      assert_equal "<p>&ldquo;smart&rdquo;</p>", @markdown.convert('"smart"').strip
-    end
-
-    should "render toc" do
-      toc = <<-TOC
-<a name="Header.1"></a>
-<h1>Header 1</h1>
-
-<a name="Header.2"></a>
-<h2>Header 2</h2>
-
-<p><ul>
- <li><a href="#Header.1">Header 1</a>
- <ul>
-  <li><a href="#Header.2">Header 2</a></li>
- </ul>
- </li>
-</ul>
-
-</p>
-TOC
-      assert_equal toc.strip,
-                   @markdown.convert("# Header 1\n\n## Header 2\n\n{:toc}").strip
-    end
-  end
-end
diff --git a/test/test_tags.rb b/test/test_tags.rb
index 739ced21..54b8e4b7 100644
--- a/test/test_tags.rb
+++ b/test/test_tags.rb
@@ -494,7 +494,7 @@ EOS
     setup do
       @content = <<CONTENT
 ---
-title: Kramdown vs. RDiscount
+title: Kramdown post with pre
 ---
 
 _FIGHT!_
@@ -507,25 +507,6 @@ puts "3..2..1.."
 CONTENT
     end
 
-    context "using RDiscount" do
-      setup do
-        if jruby?
-          then skip(
-            "JRuby does not perform well with CExt, test disabled."
-          )
-        end
-
-        create_post(@content, {
-          "markdown" => "rdiscount",
-        })
-      end
-
-      should "parse correctly" do
-        assert_match %r{<em>FIGHT!</em>}, @result
-        assert_match %r!<em>FINISH HIM</em>!, @result
-      end
-    end
-
     context "using Kramdown" do
       setup do
         create_post(@content, "markdown" => "kramdown")