diff --git a/src/actions/signup.ts b/src/actions/signup.ts
index 3db2a45..98854e0 100644
--- a/src/actions/signup.ts
+++ b/src/actions/signup.ts
@@ -66,6 +66,17 @@ export const signup = {
         });
       }
 
+      // check if user is blocked
+      if (uuid) {
+        const blockedUser = await db.getBlockedUserByUuid({ uuid: uuid });
+        if (blockedUser) {
+          throw new ActionError({
+            code: 'FORBIDDEN',
+            message: 'Du bist für die Registrierung gesperrt'
+          });
+        }
+      }
+
       if (!teamDraft) {
         // check if a team with the same name already exists
         if (input.teamName) {
diff --git a/src/actions/user.ts b/src/actions/user.ts
index ca256a7..a91eab6 100644
--- a/src/actions/user.ts
+++ b/src/actions/user.ts
@@ -84,5 +84,41 @@ export const user = {
         users: users
       };
     }
+  }),
+  addBlocked: defineAction({
+    input: z.object({
+      uuid: z.string(),
+      comment: z.string().nullable()
+    }),
+    handler: async (input, context) => {
+      Session.actionSessionFromCookies(context.cookies, Permissions.Users);
+
+      const { id } = await db.addBlockedUser(input);
+
+      return {
+        id: id
+      };
+    }
+  }),
+  editBlocked: defineAction({
+    input: z.object({
+      id: z.number(),
+      uuid: z.string(),
+      comment: z.string().nullable()
+    }),
+    handler: async (input, context) => {
+      Session.actionSessionFromCookies(context.cookies, Permissions.Users);
+
+      await db.editBlockedUser(input);
+    }
+  }),
+  blocked: defineAction({
+    handler: async (_, context) => {
+      Session.actionSessionFromCookies(context.cookies, Permissions.Users);
+
+      return {
+        blocked: await db.getBlockedUsers({})
+      };
+    }
   })
 };
diff --git a/src/app/admin/usersBlocked/CreateOrEditPopup.svelte b/src/app/admin/usersBlocked/CreateOrEditPopup.svelte
new file mode 100644
index 0000000..e1432f6
--- /dev/null
+++ b/src/app/admin/usersBlocked/CreateOrEditPopup.svelte
@@ -0,0 +1,101 @@
+<script lang="ts">
+  import Input from '@components/input/Input.svelte';
+  import Textarea from '@components/input/Textarea.svelte';
+  import { confirmPopupState } from '@components/popup/ConfirmPopup.ts';
+  import type { BlockedUser } from '@app/admin/usersBlocked/types.ts';
+  import { blockedUserCreateOrEditPopupState } from '@app/admin/usersBlocked/state.ts';
+  import { onDestroy } from 'svelte';
+
+  // html bindings
+  let modal: HTMLDialogElement;
+  let modalForm: HTMLFormElement;
+
+  // states
+  let action = $state<'create' | 'edit' | null>(null);
+  let blockedUser = $state({} as BlockedUser);
+  let onUpdate = $state((_: BlockedUser) => {});
+
+  let submitEnabled = $derived(!!blockedUser.uuid);
+
+  // lifecycle
+  const cancel = blockedUserCreateOrEditPopupState.subscribe((value) => {
+    if (value && 'create' in value) {
+      action = 'create';
+      blockedUser = {
+        id: -1,
+        uuid: '',
+        comment: null
+      };
+      onUpdate = value?.create.onUpdate;
+      modal.show();
+    } else if (value && 'edit' in value) {
+      action = 'edit';
+      blockedUser = value.edit.blockedUser;
+      onUpdate = value.edit.onUpdate;
+      modal.show();
+    }
+  });
+
+  onDestroy(cancel);
+
+  // texts
+  const texts = {
+    create: {
+      title: 'Blockierten Nutzer erstellen',
+      buttonTitle: 'Erstellen',
+      confirmPopupTitle: 'Nutzer blockieren?',
+      confirmPopupMessage:
+        'Bist du sicher, dass der Nutzer blockiert werden soll?\nEin blockierter Nutzer kann sich nicht mehr registrieren.'
+    },
+    edit: {
+      title: 'Blockierten Nutzer bearbeiten',
+      buttonTitle: 'Speichern',
+      confirmPopupTitle: 'Änderungen speichern?',
+      confirmPopupMessage: 'Sollen die Änderungen gespeichert werden?'
+    },
+    null: {}
+  };
+
+  // callbacks
+  async function onSaveButtonClick(e: Event) {
+    e.preventDefault();
+    $confirmPopupState = {
+      title: texts[action!].confirmPopupTitle,
+      message: texts[action!].confirmPopupMessage,
+      onConfirm: () => {
+        modalForm.submit();
+        onUpdate(blockedUser);
+      }
+    };
+  }
+
+  function onCancelButtonClick(e: Event) {
+    e.preventDefault();
+    modalForm.submit();
+  }
+</script>
+
+<dialog class="modal" bind:this={modal}>
+  <form method="dialog" class="modal-box" bind:this={modalForm}>
+    <button class="btn btn-sm btn-circle btn-ghost absolute right-2 top-2" onclick={onCancelButtonClick}>✕</button>
+    <div class="space-y-5">
+      <h3 class="text-xt font-geist font-bold">{texts[action!].title}</h3>
+      <div>
+        <Input bind:value={blockedUser.uuid} label="UUID" required dynamicWidth />
+        <Textarea label="Kommentar" bind:value={blockedUser.comment} rows={3} dynamicWidth />
+      </div>
+      <div>
+        <button
+          class="btn btn-success"
+          class:disabled={!submitEnabled}
+          disabled={!submitEnabled}
+          onclick={onSaveButtonClick}>{texts[action!].buttonTitle}</button
+        >
+        <button class="btn btn-error" onclick={onCancelButtonClick}>Abbrechen</button>
+      </div>
+    </div>
+  </form>
+  <form method="dialog" class="modal-backdrop bg-[rgba(0,0,0,.3)]">
+    <button class="!cursor-default">close</button>
+  </form>
+</dialog>
diff --git a/src/app/admin/usersBlocked/SidebarActions.svelte b/src/app/admin/usersBlocked/SidebarActions.svelte
new file mode 100644
index 0000000..652517f
--- /dev/null
+++ b/src/app/admin/usersBlocked/SidebarActions.svelte
@@ -0,0 +1,26 @@
+<script lang="ts">
+  import Icon from '@iconify/svelte';
+  import { addBlockedUser, fetchBlockedUsers } from '@app/admin/usersBlocked/actions.ts';
+  import { blockedUserCreateOrEditPopupState } from '@app/admin/usersBlocked/state.ts';
+
+  // lifecycle
+  $effect(() => {
+    fetchBlockedUsers();
+  });
+
+  // callbacks
+  async function onNewUserButtonClick() {
+    $blockedUserCreateOrEditPopupState = {
+      create: {
+        onUpdate: addBlockedUser
+      }
+    };
+  }
+</script>
+
+<div>
+  <button class="btn btn-soft w-full" onclick={() => onNewUserButtonClick()}>
+    <Icon icon="heroicons:plus-16-solid" />
+    <span>Neuer blockierter Nutzer</span>
+  </button>
+</div>
diff --git a/src/app/admin/usersBlocked/UsersBlocked.svelte b/src/app/admin/usersBlocked/UsersBlocked.svelte
new file mode 100644
index 0000000..0c9d9fb
--- /dev/null
+++ b/src/app/admin/usersBlocked/UsersBlocked.svelte
@@ -0,0 +1,48 @@
+<script lang="ts">
+  import Icon from '@iconify/svelte';
+  import CreateOrEditPopup from './CreateOrEditPopup.svelte';
+  import SortableTr from '@components/admin/table/SortableTr.svelte';
+  import SortableTh from '@components/admin/table/SortableTh.svelte';
+  import type { BlockedUser } from '@app/admin/usersBlocked/types.ts';
+  import { blockedUserCreateOrEditPopupState, blockedUsers } from '@app/admin/usersBlocked/state.ts';
+  import { editBlockedUser } from '@app/admin/usersBlocked/actions.ts';
+
+  // callbacks
+  async function onBlockedUserEditButtonClick(blockedUser: BlockedUser) {
+    $blockedUserCreateOrEditPopupState = {
+      edit: {
+        blockedUser: blockedUser,
+        onUpdate: editBlockedUser
+      }
+    };
+  }
+</script>
+
+<div class="h-screen overflow-x-auto">
+  <table class="table table-pin-rows">
+    <thead>
+      <SortableTr data={blockedUsers}>
+        <SortableTh style="width: 5%">#</SortableTh>
+        <SortableTh style="width: 20%" key="uuid">UUID</SortableTh>
+        <SortableTh style="width: 70%">Kommentar</SortableTh>
+        <SortableTh style="width: 5%"></SortableTh>
+      </SortableTr>
+    </thead>
+    <tbody>
+      {#each $blockedUsers as blockedUser, i (blockedUser)}
+        <tr class="hover:bg-base-200">
+          <td>{i + 1}</td>
+          <td>{blockedUser.uuid}</td>
+          <td>{blockedUser.comment}</td>
+          <td>
+            <button class="cursor-pointer" onclick={() => onBlockedUserEditButtonClick(blockedUser)}>
+              <Icon icon="heroicons:pencil-square" />
+            </button>
+          </td>
+        </tr>
+      {/each}
+    </tbody>
+  </table>
+</div>
+
+<CreateOrEditPopup />
diff --git a/src/app/admin/usersBlocked/actions.ts b/src/app/admin/usersBlocked/actions.ts
new file mode 100644
index 0000000..9c89e19
--- /dev/null
+++ b/src/app/admin/usersBlocked/actions.ts
@@ -0,0 +1,41 @@
+import { actions } from 'astro:actions';
+import { actionErrorPopup } from '@util/action.ts';
+import { blockedUsers } from '@app/admin/usersBlocked/state.ts';
+import type { BlockedUser } from '@app/admin/usersBlocked/types.ts';
+
+export async function fetchBlockedUsers() {
+  const { data, error } = await actions.user.blocked();
+  if (error) {
+    actionErrorPopup(error);
+    return;
+  }
+
+  blockedUsers.set(data.blocked);
+}
+
+export async function addBlockedUser(blockedUser: BlockedUser) {
+  const { data, error } = await actions.user.addBlocked(blockedUser);
+  if (error) {
+    actionErrorPopup(error);
+    return;
+  }
+
+  blockedUsers.update((old) => {
+    old.push(Object.assign(blockedUser, { id: data.id }));
+    return old;
+  });
+}
+
+export async function editBlockedUser(blockedUser: BlockedUser) {
+  const { data, error } = await actions.user.editBlocked(blockedUser);
+  if (error) {
+    actionErrorPopup(error);
+    return;
+  }
+
+  blockedUsers.update((old) => {
+    const index = old.findIndex((a) => a.id == user.id);
+    old[index] = blockedUser;
+    return old;
+  });
+}
diff --git a/src/app/admin/usersBlocked/state.ts b/src/app/admin/usersBlocked/state.ts
new file mode 100644
index 0000000..55ff86d
--- /dev/null
+++ b/src/app/admin/usersBlocked/state.ts
@@ -0,0 +1,6 @@
+import { writable } from 'svelte/store';
+import type { BlockedUserCreateOrEditPopupState, BlockedUsers } from '@app/admin/usersBlocked/types.ts';
+
+export const blockedUsers = writable<BlockedUsers>([]);
+
+export const blockedUserCreateOrEditPopupState = writable<BlockedUserCreateOrEditPopupState>(null);
diff --git a/src/app/admin/usersBlocked/types.ts b/src/app/admin/usersBlocked/types.ts
new file mode 100644
index 0000000..36016bc
--- /dev/null
+++ b/src/app/admin/usersBlocked/types.ts
@@ -0,0 +1,9 @@
+import { type ActionReturnType, actions } from 'astro:actions';
+
+export type BlockedUsers = Exclude<ActionReturnType<typeof actions.user.blocked>['data'], undefined>['blocked'];
+export type BlockedUser = BlockedUsers[0];
+
+export type BlockedUserCreateOrEditPopupState =
+  | { create: { onUpdate: (blockedUser: BlockedUser) => void } }
+  | { edit: { blockedUser: BlockedUser; onUpdate: (blockedUser: BlockedUser) => void } }
+  | null;
diff --git a/src/db/database.sql b/src/db/database.sql
index 2cc0350..b9e4431 100644
--- a/src/db/database.sql
+++ b/src/db/database.sql
@@ -28,6 +28,13 @@ CREATE TRIGGER IF NOT EXISTS user_username_update AFTER UPDATE ON user
     END;
 DELIMITER ;
 
+-- blocked user
+CREATE TABLE IF NOT EXISTS blocked_user (
+    id INT AUTO_INCREMENT PRIMARY KEY,
+    uuid VARCHAR(255) UNIQUE NOT NULL,
+    comment TINYTEXT
+);
+
 -- team
 CREATE TABLE IF NOT EXISTS team (
     id INT AUTO_INCREMENT PRIMARY KEY,
diff --git a/src/db/database.ts b/src/db/database.ts
index d76e31d..78eda4f 100644
--- a/src/db/database.ts
+++ b/src/db/database.ts
@@ -105,6 +105,17 @@ import {
   type GetReportStatusReq,
   reportStatus
 } from '@db/schema/reportStatus.ts';
+import {
+  addBlockedUser,
+  type AddBlockedUserReq,
+  getBlockedUsers,
+  type GetBlockedUsersReq,
+  blockedUser,
+  type GetBlockedUserByUuidReq,
+  getBlockedUserByUuid,
+  type EditBlockedUserReq,
+  editBlockedUser
+} from '@db/schema/blockedUser.ts';
 
 export class Database {
   protected readonly db: MySql2Database<{
@@ -113,6 +124,7 @@ export class Database {
     teamDraft: typeof teamDraft;
     teamMember: typeof teamMember;
     user: typeof user;
+    blockedUser: typeof blockedUser;
     death: typeof death;
     report: typeof report;
     reportStatus: typeof reportStatus;
@@ -139,6 +151,7 @@ export class Database {
         teamDraft,
         teamMember,
         user,
+        blockedUser,
         death,
         report,
         reportStatus,
@@ -173,6 +186,12 @@ export class Database {
   getUserByUsername = (values: GetUserByUsernameReq) => getUserByUsername(this.db, values);
   getUsersByUuid = (values: GetUsersByUuidReq) => getUsersByUuid(this.db, values);
 
+  /* user blocks */
+  addBlockedUser = (values: AddBlockedUserReq) => addBlockedUser(this.db, values);
+  editBlockedUser = (values: EditBlockedUserReq) => editBlockedUser(this.db, values);
+  getBlockedUserByUuid = (values: GetBlockedUserByUuidReq) => getBlockedUserByUuid(this.db, values);
+  getBlockedUsers = (values: GetBlockedUsersReq) => getBlockedUsers(this.db, values);
+
   /* team */
   addTeam = (values: AddTeamReq) => addTeam(this.db, values);
   editTeam = (values: EditTeamReq) => editTeam(this.db, values);
diff --git a/src/db/schema/blockedUser.ts b/src/db/schema/blockedUser.ts
new file mode 100644
index 0000000..528b94e
--- /dev/null
+++ b/src/db/schema/blockedUser.ts
@@ -0,0 +1,50 @@
+import { int, mysqlTable, varchar } from 'drizzle-orm/mysql-core';
+import type { MySql2Database } from 'drizzle-orm/mysql2';
+import { eq } from 'drizzle-orm';
+
+type Database = MySql2Database<{ blockedUser: typeof blockedUser }>;
+
+export const blockedUser = mysqlTable('blocked_user', {
+  id: int('id').primaryKey().autoincrement(),
+  uuid: varchar('uuid', { length: 255 }).unique().notNull(),
+  comment: varchar('comment', { length: 255 })
+});
+
+export type AddBlockedUserReq = {
+  uuid: string;
+  comment: string | null;
+};
+
+export type EditBlockedUserReq = {
+  id: number;
+  uuid: string;
+  comment: string | null;
+};
+
+export type GetBlockedUserByUuidReq = {
+  uuid: string;
+};
+
+export type GetBlockedUsersReq = {};
+
+export async function addBlockedUser(db: Database, values: AddBlockedUserReq) {
+  const bu = await db.insert(blockedUser).values(values).$returningId();
+
+  return bu[0];
+}
+
+export async function editBlockedUser(db: Database, values: EditBlockedUserReq) {
+  await db.update(blockedUser).set(values).where(eq(blockedUser.id, values.id));
+}
+
+export async function getBlockedUserByUuid(db: Database, values: GetBlockedUserByUuidReq) {
+  const bu = await db.query.blockedUser.findFirst({
+    where: eq(blockedUser.uuid, values.uuid)
+  });
+
+  return bu ?? null;
+}
+
+export async function getBlockedUsers(db: Database, _values: GetBlockedUsersReq) {
+  return db.select().from(blockedUser);
+}
diff --git a/src/layouts/admin/AdminLayout.astro b/src/layouts/admin/AdminLayout.astro
index 26810b5..af7d3e1 100644
--- a/src/layouts/admin/AdminLayout.astro
+++ b/src/layouts/admin/AdminLayout.astro
@@ -27,6 +27,13 @@ const adminTabs = [
     href: 'admin/users',
     name: 'Registrierte Nutzer',
     icon: 'heroicons:user',
+    subTabs: [
+      {
+        href: 'admin/users/blocked',
+        name: 'Blockierte Nutzer',
+        icon: 'heroicons:user-minus'
+      }
+    ],
     enabled: session?.permissions.users
   },
   {
@@ -65,7 +72,7 @@ const adminTabs = [
 <BaseLayout title={title}>
   <ClientRouter />
   <div class="flex flex-row max-h-[100vh]">
-    <ul class="menu bg-base-200 w-64 h-[100vh] flex">
+    <ul class="menu bg-base-200 w-68 h-[100vh] flex">
       {
         preTabs.map((tab) => (
           <li>
@@ -84,6 +91,18 @@ const adminTabs = [
               <Icon name={tab.icon} />
               <span>{tab.name}</span>
             </a>
+            {tab.subTabs && (
+              <ul>
+                {tab.subTabs.map((subTab) => (
+                  <li>
+                    <a href={subTab.href}>
+                      <Icon name={subTab.icon} />
+                      <span>{subTab.name}</span>
+                    </a>
+                  </li>
+                ))}
+              </ul>
+            )}
           </li>
         ))
       }
diff --git a/src/pages/admin/users/blocked.astro b/src/pages/admin/users/blocked.astro
new file mode 100644
index 0000000..9d26beb
--- /dev/null
+++ b/src/pages/admin/users/blocked.astro
@@ -0,0 +1,16 @@
+---
+import AdminLayout from '@layouts/admin/AdminLayout.astro';
+import UsersBlocked from '@app/admin/usersBlocked/UsersBlocked.svelte';
+import SidebarActions from '@app/admin/usersBlocked/SidebarActions.svelte';
+import { Session } from '@util/session.ts';
+import { Permissions } from '@util/permissions.ts';
+import { BASE_PATH } from 'astro:env/server';
+
+const session = Session.sessionFromCookies(Astro.cookies, Permissions.Admin);
+if (!session) return Astro.redirect(`${BASE_PATH}/admin`);
+---
+
+<AdminLayout title="Blockierte Nutzer">
+  <SidebarActions slot="actions" client:load />
+  <UsersBlocked client:load />
+</AdminLayout>
diff --git a/src/pages/admin/users.astro b/src/pages/admin/users/index.astro
similarity index 100%
rename from src/pages/admin/users.astro
rename to src/pages/admin/users/index.astro