diff --git a/src/librustdoc/build.rs b/src/librustdoc/build.rs
index 69337fb1d25..810225ca927 100644
--- a/src/librustdoc/build.rs
+++ b/src/librustdoc/build.rs
@@ -19,6 +19,8 @@ fn main() {
         "static/images/favicon-32x32.png",
         "static/fonts/FiraSans-Regular.woff2",
         "static/fonts/FiraSans-Medium.woff2",
+        "static/fonts/FiraMono-Regular.woff2",
+        "static/fonts/FiraMono-Medium.woff2",
         "static/fonts/FiraSans-LICENSE.txt",
         "static/fonts/SourceSerif4-Regular.ttf.woff2",
         "static/fonts/SourceSerif4-Bold.ttf.woff2",
diff --git a/src/librustdoc/html/static/css/rustdoc.css b/src/librustdoc/html/static/css/rustdoc.css
index f487d66edac..bf665bc61d6 100644
--- a/src/librustdoc/html/static/css/rustdoc.css
+++ b/src/librustdoc/html/static/css/rustdoc.css
@@ -38,6 +38,13 @@ xmlns="http://www.w3.org/2000/svg" fill="black" height="18px">\
 	--code-block-border-radius: 6px;
 	--impl-items-indent: 0.3em;
 	--docblock-indent: 24px;
+	--font-family: "Source Serif 4", NanumBarunGothic, serif;
+	--font-family-code: "Source Code Pro", monospace;
+}
+
+:root.sans-serif {
+	--font-family: "Fira Sans", sans-serif;
+	--font-family-code: "Fira Mono", monospace;
 }
 
 /* See FiraSans-LICENSE.txt for the Fira Sans license. */
@@ -57,6 +64,22 @@ xmlns="http://www.w3.org/2000/svg" fill="black" height="18px">\
 		url("FiraSans-Medium-e1aa3f0a.woff2") format("woff2");
 	font-display: swap;
 }
+@font-face {
+	font-family: 'Fira Mono';
+	font-style: normal;
+	font-weight: 400;
+	src: local('Fira Mono'),
+		url("FiraMono-Regular-87c26294.woff2") format("woff2");
+	font-display: swap;
+}
+@font-face {
+	font-family: 'Fira Mono';
+	font-style: normal;
+	font-weight: 500;
+	src: local('Fira Mono Medium'),
+		url("FiraMono-Medium-86f75c8c.woff2") format("woff2");
+	font-display: swap;
+}
 
 /* See SourceSerif4-LICENSE.md for the Source Serif 4 license. */
 @font-face {
@@ -126,7 +149,7 @@ xmlns="http://www.w3.org/2000/svg" fill="black" height="18px">\
 body {
 	/* Line spacing at least 1.5 per Web Content Accessibility Guidelines
 	   https://www.w3.org/WAI/WCAG21/Understanding/visual-presentation.html */
-	font: 1rem/1.5 "Source Serif 4", NanumBarunGothic, serif;
+	font: 1rem/1.5 var(--font-family);
 	margin: 0;
 	position: relative;
 	/* We use overflow-wrap: break-word for Safari, which doesn't recognize
@@ -380,7 +403,7 @@ details:not(.toggle) summary {
 }
 
 code, pre, .code-header, .type-signature {
-	font-family: "Source Code Pro", monospace;
+	font-family: var(--font-family-code)
 }
 .docblock code, .item-table dd code {
 	border-radius: 3px;
diff --git a/src/librustdoc/html/static/fonts/FiraMono-Medium.woff2 b/src/librustdoc/html/static/fonts/FiraMono-Medium.woff2
new file mode 100755
index 00000000000..610e9b2071e
Binary files /dev/null and b/src/librustdoc/html/static/fonts/FiraMono-Medium.woff2 differ
diff --git a/src/librustdoc/html/static/fonts/FiraMono-Regular.woff2 b/src/librustdoc/html/static/fonts/FiraMono-Regular.woff2
new file mode 100755
index 00000000000..9fa44b7cc2d
Binary files /dev/null and b/src/librustdoc/html/static/fonts/FiraMono-Regular.woff2 differ
diff --git a/src/librustdoc/html/static/js/settings.js b/src/librustdoc/html/static/js/settings.js
index 183663b94fc..245159d8e05 100644
--- a/src/librustdoc/html/static/js/settings.js
+++ b/src/librustdoc/html/static/js/settings.js
@@ -50,6 +50,12 @@
                     removeClass(document.documentElement, "hide-modnav");
                 }
                 break;
+            case "sans-serif-fonts":
+                if (value === true) {
+                    addClass(document.documentElement, "sans-serif");
+                } else {
+                    removeClass(document.documentElement, "sans-serif");
+                }
         }
     }
 
@@ -232,6 +238,11 @@
                 "js_name": "disable-shortcuts",
                 "default": false,
             },
+            {
+                "name": "Use sans serif fonts",
+                "js_name": "sans-serif-fonts",
+                "default": false,
+            },
         ];
 
         // Then we build the DOM.
diff --git a/src/librustdoc/html/static/js/storage.js b/src/librustdoc/html/static/js/storage.js
index d77804d045e..1867e4cc0f3 100644
--- a/src/librustdoc/html/static/js/storage.js
+++ b/src/librustdoc/html/static/js/storage.js
@@ -211,6 +211,9 @@ if (getSettingValue("hide-toc") === "true") {
 if (getSettingValue("hide-modnav") === "true") {
     addClass(document.documentElement, "hide-modnav");
 }
+if (getSettingValue("sans-serif-fonts") === "true") {
+    addClass(document.documentElement, "sans-serif");
+}
 function updateSidebarWidth() {
     const desktopSidebarWidth = getSettingValue("desktop-sidebar-width");
     if (desktopSidebarWidth && desktopSidebarWidth !== "null") {
diff --git a/src/librustdoc/html/static_files.rs b/src/librustdoc/html/static_files.rs
index 6457ac731cb..ec59353948d 100644
--- a/src/librustdoc/html/static_files.rs
+++ b/src/librustdoc/html/static_files.rs
@@ -100,6 +100,8 @@ static_files! {
     rust_favicon_png_32 => "static/images/favicon-32x32.png",
     fira_sans_regular => "static/fonts/FiraSans-Regular.woff2",
     fira_sans_medium => "static/fonts/FiraSans-Medium.woff2",
+    fira_mono_regular => "static/fonts/FiraMono-Regular.woff2",
+    fira_mono_medium => "static/fonts/FiraMono-Medium.woff2",
     fira_sans_license => "static/fonts/FiraSans-LICENSE.txt",
     source_serif_4_regular => "static/fonts/SourceSerif4-Regular.ttf.woff2",
     source_serif_4_bold => "static/fonts/SourceSerif4-Bold.ttf.woff2",