diff --git a/package.json b/package.json
index 1b77452d1c..2477232ed9 100644
--- a/package.json
+++ b/package.json
@@ -54,7 +54,8 @@
   "pnpm": {
     "patchedDependencies": {
       "readable-stream@2.3.8": "patches/readable-stream@2.3.8.patch",
-      "comark@0.6.2": "patches/comark@0.6.2.patch"
+      "comark@0.6.2": "patches/comark@0.6.2.patch",
+      "beautiful-mermaid@1.1.3": "patches/beautiful-mermaid@1.1.3.patch"
     },
     "peerDependencyRules": {
       "allowedVersions": {
diff --git a/packages/assets/styles/classes.scss b/packages/assets/styles/classes.scss
index 69c4615458..ab32774ee1 100644
--- a/packages/assets/styles/classes.scss
+++ b/packages/assets/styles/classes.scss
@@ -953,6 +953,18 @@ a:not(.no-click-animation),
 		}
 	}
 
+	.mermaid {
+		@apply bg-surface-2 rounded-xl p-4 border border-solid border-surface-5;
+		margin-top: 1rem;
+		overflow-x: auto;
+
+		svg {
+			width: 100%;
+			max-width: 32rem;
+			height: auto;
+		}
+	}
+
 	code {
 		@apply bg-surface-3 rounded-md p-4 border border-solid border-surface-5;
 		padding: 0.2em 0.4em;
diff --git a/packages/ui/package.json b/packages/ui/package.json
index a1b22d3675..809ad59018 100644
--- a/packages/ui/package.json
+++ b/packages/ui/package.json
@@ -74,6 +74,7 @@
 		"@xterm/xterm": "^6.0.0",
 		"ace-builds": "^1.43.5",
 		"apexcharts": "^4.0.0",
+		"beautiful-mermaid": "^1.1.3",
 		"comark": "^0.6.2",
 		"dayjs": "^1.11.10",
 		"dompurify": "^3.1.7",
diff --git a/packages/ui/src/components/base/MarkdownBody.vue b/packages/ui/src/components/base/MarkdownBody.vue
index 18cecec1fa..669a2ba36d 100644
--- a/packages/ui/src/components/base/MarkdownBody.vue
+++ b/packages/ui/src/components/base/MarkdownBody.vue
@@ -35,6 +35,7 @@ import { computed } from 'vue'
 import MarkdownAlert, { alertMarkerTypes } from './markdown/MarkdownAlert.vue'
 import MarkdownCollectionEmbed from './markdown/MarkdownCollectionEmbed.vue'
 import MarkdownHighlightedPre from './markdown/MarkdownHighlightedPre.vue'
+import MarkdownMermaid from './markdown/MarkdownMermaid.vue'
 import MarkdownOrganizationEmbed from './markdown/MarkdownOrganizationEmbed.vue'
 import MarkdownProjectEmbed from './markdown/MarkdownProjectEmbed.vue'
 import MarkdownTaskCheckbox from './markdown/MarkdownTaskCheckbox.vue'
@@ -84,6 +85,7 @@ const components = computed(() =>
 				organization: MarkdownOrganizationEmbed,
 				collection: MarkdownCollectionEmbed,
 				input: MarkdownTaskCheckbox,
+				mermaid: MarkdownMermaid,
 				...(props.highlight ? { pre: MarkdownHighlightedPre } : {}),
 			},
 )
diff --git a/packages/ui/src/components/base/markdown/MarkdownMermaid.vue b/packages/ui/src/components/base/markdown/MarkdownMermaid.vue
new file mode 100644
index 0000000000..a348499408
--- /dev/null
+++ b/packages/ui/src/components/base/markdown/MarkdownMermaid.vue
@@ -0,0 +1,29 @@
+<template>
+	<Mermaid :content="content" :theme="resolvedTheme" :theme-dark="resolvedThemeDark" />
+</template>
+
+<script setup lang="ts">
+import { Mermaid } from '@comark/vue/plugins/mermaid'
+import type { ThemeNames } from 'comark/plugins/mermaid'
+import type { DiagramColors } from 'beautiful-mermaid'
+import { computed } from 'vue'
+
+const modrinthMermaidTheme: DiagramColors = {
+	bg: 'var(--surface-2)',
+	fg: 'var(--color-contrast)',
+	line: 'var(--color-secondary)',
+	accent: 'var(--color-brand)',
+	muted: 'var(--color-secondary)',
+	surface: 'var(--color-button-bg)',
+	border: 'var(--color-divider)',
+}
+
+const props = defineProps<{
+	content: string
+	theme?: ThemeNames
+	themeDark?: ThemeNames
+}>()
+
+const resolvedTheme = computed(() => props.theme ?? modrinthMermaidTheme)
+const resolvedThemeDark = computed(() => props.themeDark ?? modrinthMermaidTheme)
+</script>
diff --git a/packages/utils/markdown/parse.ts b/packages/utils/markdown/parse.ts
index 6e8693a11f..c307504252 100644
--- a/packages/utils/markdown/parse.ts
+++ b/packages/utils/markdown/parse.ts
@@ -11,6 +11,7 @@ import components from 'comark/plugins/components'
 import emoji from 'comark/plugins/emoji'
 import footnotes from 'comark/plugins/footnotes'
 import html from 'comark/plugins/html'
+import mermaid from 'comark/plugins/mermaid'
 import punctuation from 'comark/plugins/punctuation'
 import taskList from 'comark/plugins/task-list'
 import { visitAsync } from 'comark/utils'
@@ -48,7 +49,7 @@ export const modrinthPlugins: ComarkPlugin[] = [
 	modrinthHtmlBlock(),
 	// json-render()
 	// math(), // needs dep
-	// mermaid(), // needs dep
+	mermaid(),
 	punctuation(),
 	// rangi() // needs dep + we have highlight.js + if we do want to switch I'd say shiki is better
 	modrinthEmbedSyntax(),
diff --git a/packages/utils/markdown/security.ts b/packages/utils/markdown/security.ts
index f757399c22..748a947fbd 100644
--- a/packages/utils/markdown/security.ts
+++ b/packages/utils/markdown/security.ts
@@ -93,6 +93,7 @@ export const attributeAllowlist: Record<string, string[]> = {
 	li: ['class'],
 	map: ['name'],
 	mark: [],
+	mermaid: ['content', 'theme', 'theme-dark', 'class'],
 	nav: [],
 	ol: [],
 	organization: ['id'],
diff --git a/patches/beautiful-mermaid@1.1.3.patch b/patches/beautiful-mermaid@1.1.3.patch
new file mode 100644
index 0000000000..8f464a4444
--- /dev/null
+++ b/patches/beautiful-mermaid@1.1.3.patch
@@ -0,0 +1,56 @@
+diff --git a/dist/index.js b/dist/index.js
+index e7e087bcb6f29d0d8f36cd558e0183bc0f162fcb..500c550c2723be4e84775afbb680dc1e06351451 100644
+--- a/dist/index.js
++++ b/dist/index.js
+@@ -6985,14 +6985,18 @@ function markerSuffix(color) {
+ function renderGroup(group, font) {
+   const headerHeight = FONT_SIZES.groupHeader + 16;
+   const parts = [];
++  const clipId = `group-clip-${group.id.replace(/[^a-zA-Z0-9_-]/g, "_")}`;
++  parts.push(
++    `<clipPath id="${clipId}"><rect x="${group.x}" y="${group.y}" width="${group.width}" height="${group.height}" rx="8" ry="8" /></clipPath>`
++  );
+   parts.push(
+     `<g class="subgraph" data-id="${escapeAttr(group.id)}" data-label="${escapeAttr(group.label)}">`
+   );
+   parts.push(
+-    `  <rect x="${group.x}" y="${group.y}" width="${group.width}" height="${group.height}" rx="0" ry="0" fill="var(--_group-fill)" stroke="var(--_node-stroke)" stroke-width="${STROKE_WIDTHS.outerBox}" />`
++    `  <rect x="${group.x}" y="${group.y}" width="${group.width}" height="${group.height}" rx="8" ry="8" fill="var(--_group-fill)" stroke="var(--_node-stroke)" stroke-width="${STROKE_WIDTHS.outerBox}" />`
+   );
+   parts.push(
+-    `  <rect x="${group.x}" y="${group.y}" width="${group.width}" height="${headerHeight}" rx="0" ry="0" fill="var(--_group-hdr)" stroke="var(--_node-stroke)" stroke-width="${STROKE_WIDTHS.outerBox}" />`
++    `  <rect x="${group.x}" y="${group.y}" width="${group.width}" height="${headerHeight}" fill="var(--_group-hdr)" stroke="var(--_node-stroke)" stroke-width="${STROKE_WIDTHS.outerBox}" clip-path="url(#${clipId})" />`
+   );
+   parts.push(
+     "  " + renderMultilineText(
+@@ -7134,10 +7138,10 @@ function renderNodeShape(node) {
+   }
+ }
+ function renderRect(x, y, w, h, fill, stroke, sw) {
+-  return `<rect x="${x}" y="${y}" width="${w}" height="${h}" rx="0" ry="0" fill="${fill}" stroke="${stroke}" stroke-width="${sw}" />`;
++  return `<rect x="${x}" y="${y}" width="${w}" height="${h}" rx="6" ry="6" fill="${fill}" stroke="${stroke}" stroke-width="${sw}" />`;
+ }
+ function renderRoundedRect(x, y, w, h, fill, stroke, sw) {
+-  return `<rect x="${x}" y="${y}" width="${w}" height="${h}" rx="6" ry="6" fill="${fill}" stroke="${stroke}" stroke-width="${sw}" />`;
++  return `<rect x="${x}" y="${y}" width="${w}" height="${h}" rx="10" ry="10" fill="${fill}" stroke="${stroke}" stroke-width="${sw}" />`;
+ }
+ function renderStadium(x, y, w, h, fill, stroke, sw) {
+   const r2 = h / 2;
+@@ -7168,7 +7172,7 @@ function renderDiamond(x, y, w, h, fill, stroke, sw) {
+ }
+ function renderSubroutine(x, y, w, h, fill, stroke, sw) {
+   const inset = 8;
+-  return `<rect x="${x}" y="${y}" width="${w}" height="${h}" rx="0" ry="0" fill="${fill}" stroke="${stroke}" stroke-width="${sw}" />
++  return `<rect x="${x}" y="${y}" width="${w}" height="${h}" rx="6" ry="6" fill="${fill}" stroke="${stroke}" stroke-width="${sw}" />
+ <line x1="${x + inset}" y1="${y}" x2="${x + inset}" y2="${y + h}" stroke="${stroke}" stroke-width="${sw}" />
+ <line x1="${x + w - inset}" y1="${y}" x2="${x + w - inset}" y2="${y + h}" stroke="${stroke}" stroke-width="${sw}" />`;
+ }
+@@ -7645,7 +7649,7 @@ function renderActor(actor) {
+   } else {
+     const boxX = x - width / 2;
+     parts.push(
+-      `  <rect x="${boxX}" y="${y}" width="${width}" height="${height}" rx="4" ry="4" fill="var(--_node-fill)" stroke="var(--_node-stroke)" stroke-width="${STROKE_WIDTHS.outerBox}" />`
++      `  <rect x="${boxX}" y="${y}" width="${width}" height="${height}" rx="8" ry="8" fill="var(--_node-fill)" stroke="var(--_node-stroke)" stroke-width="${STROKE_WIDTHS.outerBox}" />`
+     );
+     parts.push(
+       "  " + renderMultilineText(
diff --git a/patches/comark@0.6.2.patch b/patches/comark@0.6.2.patch
index f8053d6cb6..4cc3ed7bb8 100644
--- a/patches/comark@0.6.2.patch
+++ b/patches/comark@0.6.2.patch
@@ -1,8 +1,8 @@
 diff --git a/dist/internal/parse/token-processor.js b/dist/internal/parse/token-processor.js
-index 440841f8d9252067681f09df935dd0287fff2cf0..71c44f24a932a1f900329800f28029206aa5a13f 100644
+index 440841f8d9252067681f09df935dd0287fff2cf0..e71c6f763d8520c53d7f7d8a1e9bcdc5e29f0526 100644
 --- a/dist/internal/parse/token-processor.js
 +++ b/dist/internal/parse/token-processor.js
-@@ -483,6 +483,20 @@ function processBlockChildren(tokens, startIndex, closeType, inlineOnly, inHeadi
+@@ -483,6 +483,16 @@ function processBlockChildren(tokens, startIndex, closeType, inlineOnly, inHeadi
              }
              i++;
          }
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 7ce89af57f..3137a64ff9 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -5,8 +5,11 @@ settings:
   excludeLinksFromLockfile: false
 
 patchedDependencies:
+  beautiful-mermaid@1.1.3:
+    hash: 51834efb99f2945be29ce3a3cbc45a3b9ff4cde6ca80ba6d2c22e85d9b9cbd47
+    path: patches/beautiful-mermaid@1.1.3.patch
   comark@0.6.2:
-    hash: 4e73fba3ed127a788219ec2e7a413966f48fc7695802a1b0f2694ef2686d475c
+    hash: c8af805d46dd2a152fda357d551ed56a0a876f61520b78ad6fe250b82afd17f8
     path: patches/comark@0.6.2.patch
   readable-stream@2.3.8:
     hash: 3045f7adf989b4e668a4a13819b7285b0de186b79bbf22408acaf2a41c6eaa86
@@ -654,7 +657,7 @@ importers:
         version: 6.39.12
       '@comark/vue':
         specifier: ^0.6.2
-        version: 0.6.2(vue@3.5.27(typescript@5.9.3))
+        version: 0.6.2(beautiful-mermaid@1.1.3(patch_hash=51834efb99f2945be29ce3a3cbc45a3b9ff4cde6ca80ba6d2c22e85d9b9cbd47))(vue@3.5.27(typescript@5.9.3))
       '@intercom/messenger-js-sdk':
         specifier: ^0.0.14
         version: 0.0.14
@@ -709,9 +712,12 @@ importers:
       apexcharts:
         specifier: ^4.0.0
         version: 4.7.0
+      beautiful-mermaid:
+        specifier: ^1.1.3
+        version: 1.1.3(patch_hash=51834efb99f2945be29ce3a3cbc45a3b9ff4cde6ca80ba6d2c22e85d9b9cbd47)
       comark:
         specifier: ^0.6.2
-        version: 0.6.2(patch_hash=4e73fba3ed127a788219ec2e7a413966f48fc7695802a1b0f2694ef2686d475c)
+        version: 0.6.2(patch_hash=c8af805d46dd2a152fda357d551ed56a0a876f61520b78ad6fe250b82afd17f8)(beautiful-mermaid@1.1.3(patch_hash=51834efb99f2945be29ce3a3cbc45a3b9ff4cde6ca80ba6d2c22e85d9b9cbd47))
       dayjs:
         specifier: ^1.11.10
         version: 1.11.19
@@ -856,13 +862,13 @@ importers:
         version: 6.39.12
       '@comark/html':
         specifier: ^0.6.2
-        version: 0.6.2
+        version: 0.6.2(beautiful-mermaid@1.1.3(patch_hash=51834efb99f2945be29ce3a3cbc45a3b9ff4cde6ca80ba6d2c22e85d9b9cbd47))
       '@types/three':
         specifier: ^0.172.0
         version: 0.172.0
       comark:
         specifier: ^0.6.2
-        version: 0.6.2(patch_hash=4e73fba3ed127a788219ec2e7a413966f48fc7695802a1b0f2694ef2686d475c)
+        version: 0.6.2(patch_hash=c8af805d46dd2a152fda357d551ed56a0a876f61520b78ad6fe250b82afd17f8)(beautiful-mermaid@1.1.3(patch_hash=51834efb99f2945be29ce3a3cbc45a3b9ff4cde6ca80ba6d2c22e85d9b9cbd47))
       dayjs:
         specifier: ^1.11.10
         version: 1.11.19
@@ -5571,6 +5577,9 @@ packages:
   bcp-47@2.1.0:
     resolution: {integrity: sha512-9IIS3UPrvIa1Ej+lVDdDwO7zLehjqsaByECw0bu2RRGP73jALm6FYbzI5gWbgHLvNdkvfXB5YrSbocZdOS0c0w==}
 
+  beautiful-mermaid@1.1.3:
+    resolution: {integrity: sha512-TItrtrAyHp1vwFfFVYauWGrquouk/6SS21Aq3RsxindSYZODcN4xYrPZD6BiZRU+o5mKJzDPz9MUSMvELdylyg==}
+
   binary-extensions@2.3.0:
     resolution: {integrity: sha512-Ceh+7ox5qe7LJuLHoY0feh3pHuUDHAcRUeyL2VYghZwfpkNIy/+8Ocg0a3UuSoYzavmylwuLWQOf3hl0jjMMIw==}
     engines: {node: '>=8'}
@@ -6242,6 +6251,9 @@ packages:
   electron-to-chromium@1.5.286:
     resolution: {integrity: sha512-9tfDXhJ4RKFNerfjdCcZfufu49vg620741MNs26a9+bhLThdB+plgMeou98CAaHu/WATj2iHOOHTp1hWtABj2A==}
 
+  elkjs@0.11.1:
+    resolution: {integrity: sha512-zxxR9k+rx5ktMwT/FwyLdPCrq7xN6e4VGGHH8hA01vVYKjTFik7nHOxBnAYtrgYUB1RpAiLvA1/U2YraWxyKKg==}
+
   emmet@2.4.11:
     resolution: {integrity: sha512-23QPJB3moh/U9sT4rQzGgeyyGIrcM+GH5uVYg2C6wZIxAIJq7Ng3QLT79tl8FUwDXhyq9SusfknOrofAKqvgyQ==}
 
@@ -11308,16 +11320,20 @@ snapshots:
       style-mod: 4.1.3
       w3c-keyname: 2.2.8
 
-  '@comark/html@0.6.2':
+  '@comark/html@0.6.2(beautiful-mermaid@1.1.3(patch_hash=51834efb99f2945be29ce3a3cbc45a3b9ff4cde6ca80ba6d2c22e85d9b9cbd47))':
     dependencies:
-      comark: 0.6.2(patch_hash=4e73fba3ed127a788219ec2e7a413966f48fc7695802a1b0f2694ef2686d475c)
+      comark: 0.6.2(patch_hash=c8af805d46dd2a152fda357d551ed56a0a876f61520b78ad6fe250b82afd17f8)(beautiful-mermaid@1.1.3(patch_hash=51834efb99f2945be29ce3a3cbc45a3b9ff4cde6ca80ba6d2c22e85d9b9cbd47))
+    optionalDependencies:
+      beautiful-mermaid: 1.1.3(patch_hash=51834efb99f2945be29ce3a3cbc45a3b9ff4cde6ca80ba6d2c22e85d9b9cbd47)
     transitivePeerDependencies:
       - rangi
 
-  '@comark/vue@0.6.2(vue@3.5.27(typescript@5.9.3))':
+  '@comark/vue@0.6.2(beautiful-mermaid@1.1.3(patch_hash=51834efb99f2945be29ce3a3cbc45a3b9ff4cde6ca80ba6d2c22e85d9b9cbd47))(vue@3.5.27(typescript@5.9.3))':
     dependencies:
-      comark: 0.6.2(patch_hash=4e73fba3ed127a788219ec2e7a413966f48fc7695802a1b0f2694ef2686d475c)
+      comark: 0.6.2(patch_hash=c8af805d46dd2a152fda357d551ed56a0a876f61520b78ad6fe250b82afd17f8)(beautiful-mermaid@1.1.3(patch_hash=51834efb99f2945be29ce3a3cbc45a3b9ff4cde6ca80ba6d2c22e85d9b9cbd47))
       vue: 3.5.27(typescript@5.9.3)
+    optionalDependencies:
+      beautiful-mermaid: 1.1.3(patch_hash=51834efb99f2945be29ce3a3cbc45a3b9ff4cde6ca80ba6d2c22e85d9b9cbd47)
     transitivePeerDependencies:
       - rangi
 
@@ -15692,6 +15708,11 @@ snapshots:
       is-alphanumerical: 2.0.1
       is-decimal: 2.0.1
 
+  beautiful-mermaid@1.1.3(patch_hash=51834efb99f2945be29ce3a3cbc45a3b9ff4cde6ca80ba6d2c22e85d9b9cbd47):
+    dependencies:
+      elkjs: 0.11.1
+      entities: 7.0.1
+
   binary-extensions@2.3.0: {}
 
   bindings@1.5.0:
@@ -15951,12 +15972,14 @@ snapshots:
 
   colord@2.9.3: {}
 
-  comark@0.6.2(patch_hash=4e73fba3ed127a788219ec2e7a413966f48fc7695802a1b0f2694ef2686d475c):
+  comark@0.6.2(patch_hash=c8af805d46dd2a152fda357d551ed56a0a876f61520b78ad6fe250b82afd17f8)(beautiful-mermaid@1.1.3(patch_hash=51834efb99f2945be29ce3a3cbc45a3b9ff4cde6ca80ba6d2c22e85d9b9cbd47)):
     dependencies:
       entities: 8.0.0
       htmlparser2: 12.0.0
       js-yaml: 5.3.0
       markdown-exit: 1.1.0-beta.2
+    optionalDependencies:
+      beautiful-mermaid: 1.1.3(patch_hash=51834efb99f2945be29ce3a3cbc45a3b9ff4cde6ca80ba6d2c22e85d9b9cbd47)
 
   combined-stream@1.0.8:
     dependencies:
@@ -16323,6 +16346,8 @@ snapshots:
 
   electron-to-chromium@1.5.286: {}
 
+  elkjs@0.11.1: {}
+
   emmet@2.4.11:
     dependencies:
       '@emmetio/abbreviation': 2.3.3