diff --git a/web/roles/create-roles-modal.css b/web/roles/create-roles-modal.css
index bf34ddc85..603634029 100644
--- a/web/roles/create-roles-modal.css
+++ b/web/roles/create-roles-modal.css
@@ -1,72 +1,83 @@
 .formContainer {
   display: flex;
   flex-direction: column;
   padding: 16px 32px 0 32px;
 }
 
 .roleNameLabel {
   color: var(--create-roles-text-color);
   padding: 4px 0;
   margin-top: 20px;
 }
 
 .roleNameInput {
   display: flex;
   color: var(--fg);
   margin: 8px 0 12px 0;
 }
 
+.errorMessage {
+  color: var(--error);
+  font-size: var(--s-font-14);
+  align-self: center;
+  visibility: hidden;
+}
+
+.errorMessageVisible {
+  visibility: visible;
+}
+
 .separator {
   border: 0;
   margin: 16px 32px 8px 32px;
   width: 90%;
   align-self: center;
   height: 2px;
   border: none;
   border-top: var(--modal-separator) solid 1px;
 }
 
 .permissionsHeaderContainer {
   display: flex;
   flex-direction: row;
   justify-content: space-between;
   padding: 16px 32px 24px 32px;
 }
 
 .permissionsLabel {
   color: var(--create-roles-text-color);
 }
 
 .clearPermissions {
   font-size: var(--s-font-14);
 }
 
 .clearPermissionsDisabled {
   color: var(--color-disabled);
   cursor: not-allowed;
 }
 
 .clearPermissionsEnabled {
   color: var(--purple-link);
   cursor: pointer;
 }
 
 .permissionsContainer {
   max-height: 350px;
   overflow-y: auto;
 }
 
 .buttonsContainer {
   display: flex;
   flex-direction: row;
   justify-content: flex-end;
   padding: 16px 32px;
 }
 
 .backButton {
   width: 100px;
 }
 
 .createRoleButton {
   margin-left: 8px;
 }
diff --git a/web/roles/create-roles-modal.react.js b/web/roles/create-roles-modal.react.js
index 70fe61dda..a114b4534 100644
--- a/web/roles/create-roles-modal.react.js
+++ b/web/roles/create-roles-modal.react.js
@@ -1,258 +1,293 @@
 // @flow
 
 import classNames from 'classnames';
 import invariant from 'invariant';
 import * as React from 'react';
 
 import {
   modifyCommunityRole,
   modifyCommunityRoleActionTypes,
 } from 'lib/actions/thread-actions.js';
 import { useModalContext } from 'lib/components/modal-provider.react.js';
 import { createLoadingStatusSelector } from 'lib/selectors/loading-selectors.js';
 import type { LoadingStatus } from 'lib/types/loading-types.js';
 import type {
   UserSurfacedPermission,
   UserSurfacedPermissionOption,
 } from 'lib/types/thread-permission-types.js';
 import type {
   ThreadInfo,
   RoleModificationRequest,
 } from 'lib/types/thread-types.js';
 import {
   useServerCall,
   useDispatchActionPromise,
 } from 'lib/utils/action-utils.js';
+import { values } from 'lib/utils/objects.js';
 import { useFilterPermissionOptionsByThreadType } from 'lib/utils/role-utils.js';
 
 import css from './create-roles-modal.css';
 import Button, { buttonThemes } from '../components/button.react.js';
 import EnumSettingsOption from '../components/enum-settings-option.react.js';
 import LoadingIndicator from '../loading-indicator.react.js';
 import Input from '../modals/input.react.js';
 import Modal from '../modals/modal.react.js';
 import UnsavedChangesModal from '../modals/unsaved-changes-modal.react.js';
 import { useSelector } from '../redux/redux-utils.js';
 
 const createRolesLoadingStatusSelector = createLoadingStatusSelector(
   modifyCommunityRoleActionTypes,
 );
 
 type CreateRolesModalProps = {
   +threadInfo: ThreadInfo,
   +action: 'create_role' | 'edit_role',
   +existingRoleID?: string,
   +roleName: string,
   +rolePermissions: $ReadOnlySet<UserSurfacedPermission>,
 };
 
+type RoleCreationErrorVariant = 'already_exists' | 'unknown_error';
+
 function CreateRolesModal(props: CreateRolesModalProps): React.Node {
   const { pushModal, popModal } = useModalContext();
   const { threadInfo, action, existingRoleID, roleName, rolePermissions } =
     props;
 
   const callModifyCommunityRole = useServerCall(modifyCommunityRole);
   const dispatchActionPromise = useDispatchActionPromise();
 
   const createRolesLoadingStatus: LoadingStatus = useSelector(
     createRolesLoadingStatusSelector,
   );
 
   const [pendingRoleName, setPendingRoleName] =
     React.useState<string>(roleName);
   const [pendingRolePermissions, setPendingRolePermissions] =
     React.useState<$ReadOnlySet<UserSurfacedPermission>>(rolePermissions);
 
+  const [roleCreationFailed, setRoleCreationFailed] =
+    React.useState<?RoleCreationErrorVariant>();
+
   const onChangeRoleName = React.useCallback(
     (event: SyntheticEvent<HTMLInputElement>) => {
+      setRoleCreationFailed(null);
       setPendingRoleName(event.currentTarget.value);
     },
     [],
   );
 
   const onCloseModal = React.useCallback(() => {
     const pendingSet = new Set(pendingRolePermissions);
     const roleSet = new Set(rolePermissions);
 
     let arePermissionsEqual = true;
     if (pendingSet.size !== roleSet.size) {
       arePermissionsEqual = false;
     }
     for (const permission of pendingSet) {
       if (!roleSet.has(permission)) {
         arePermissionsEqual = false;
         break;
       }
     }
 
     if (pendingRoleName === roleName && arePermissionsEqual) {
       popModal();
       return;
     }
 
     pushModal(<UnsavedChangesModal />);
   }, [
     pendingRoleName,
     roleName,
     pendingRolePermissions,
     rolePermissions,
     pushModal,
     popModal,
   ]);
 
   const clearPermissionsClassNames = classNames({
     [css.clearPermissions]: true,
     [css.clearPermissionsDisabled]: pendingRolePermissions.size === 0,
     [css.clearPermissionsEnabled]: pendingRolePermissions.size > 0,
   });
 
   const onClearPermissions = React.useCallback(
     () => setPendingRolePermissions(new Set()),
     [],
   );
 
   const isUserSurfacedPermissionSelected = React.useCallback(
     (option: UserSurfacedPermissionOption) =>
       pendingRolePermissions.has(option.userSurfacedPermission),
     [pendingRolePermissions],
   );
 
   const onEnumValuePress = React.useCallback(
     (option: UserSurfacedPermissionOption) =>
       setPendingRolePermissions(currentPermissions => {
         if (currentPermissions.has(option.userSurfacedPermission)) {
           const newPermissions = new Set(currentPermissions);
           newPermissions.delete(option.userSurfacedPermission);
           return newPermissions;
         } else {
           return new Set([
             ...currentPermissions,
             option.userSurfacedPermission,
           ]);
         }
       }),
     [],
   );
 
   const filteredUserSurfacedPermissionOptions =
     useFilterPermissionOptionsByThreadType(threadInfo.type);
 
   const permissionsList = React.useMemo(
     () =>
       [...filteredUserSurfacedPermissionOptions].map(permission => (
         <EnumSettingsOption
           key={permission.userSurfacedPermission}
           selected={isUserSurfacedPermissionSelected(permission)}
           onSelect={() => onEnumValuePress(permission)}
           icon={null}
           title={permission.title}
           type="checkbox"
           statements={[{ statement: permission.description }]}
         />
       )),
     [
       filteredUserSurfacedPermissionOptions,
       isUserSurfacedPermissionSelected,
       onEnumValuePress,
     ],
   );
 
+  const errorMessageClassNames = classNames({
+    [css.errorMessage]: true,
+    [css.errorMessageVisible]: !!roleCreationFailed,
+  });
+
+  const threadRoleNames = React.useMemo(
+    () => values(threadInfo.roles).map(role => role.name),
+    [threadInfo],
+  );
+
   const onClickCreateRole = React.useCallback(() => {
-    // TODO: Error handling in a later diff
+    if (threadRoleNames.includes(pendingRoleName) && action === 'create_role') {
+      setRoleCreationFailed('already_exists');
+      return;
+    }
 
     let callModifyCommunityRoleParams: RoleModificationRequest;
     if (action === 'create_role') {
       callModifyCommunityRoleParams = {
         community: threadInfo.id,
         action,
         name: pendingRoleName,
         permissions: [...pendingRolePermissions],
       };
     } else {
       invariant(existingRoleID, 'existingRoleID should be defined');
       callModifyCommunityRoleParams = {
         community: threadInfo.id,
         existingRoleID,
         action,
         name: pendingRoleName,
         permissions: [...pendingRolePermissions],
       };
     }
 
     dispatchActionPromise(
       modifyCommunityRoleActionTypes,
       (async () => {
-        const response = await callModifyCommunityRole(
-          callModifyCommunityRoleParams,
-        );
-        popModal();
-        return response;
+        try {
+          const response = await callModifyCommunityRole(
+            callModifyCommunityRoleParams,
+          );
+          popModal();
+          return response;
+        } catch (e) {
+          setRoleCreationFailed('unknown_error');
+          throw e;
+        }
       })(),
     );
   }, [
     callModifyCommunityRole,
     dispatchActionPromise,
     threadInfo,
     action,
     existingRoleID,
     pendingRoleName,
     pendingRolePermissions,
     popModal,
+    threadRoleNames,
   ]);
 
+  const errorMessage = React.useMemo(() => {
+    if (roleCreationFailed === 'already_exists') {
+      return 'There is already a role with this name in the community';
+    } else {
+      return 'An unknown error occurred. Please try again';
+    }
+  }, [roleCreationFailed]);
+
   const saveButtonContent = React.useMemo(() => {
     if (createRolesLoadingStatus === 'loading') {
       return (
         <LoadingIndicator status={createRolesLoadingStatus} size="medium" />
       );
     }
 
     return 'Save';
   }, [createRolesLoadingStatus]);
 
   return (
     <Modal name="Create Role" onClose={onCloseModal} size="large">
       <form method="POST" className={css.formContainer}>
         <div className={css.roleNameLabel}>Role Name</div>
         <div className={css.roleNameInput}>
           <Input
             type="text"
             value={pendingRoleName}
             onChange={onChangeRoleName}
           />
         </div>
+        <div className={errorMessageClassNames}>{errorMessage}</div>
       </form>
       <hr className={css.separator} />
       <div className={css.permissionsHeaderContainer}>
         <div className={css.permissionsLabel}>Permissions</div>
         <div
           className={clearPermissionsClassNames}
           onClick={onClearPermissions}
         >
           Clear Permissions
         </div>
       </div>
       <div className={css.permissionsContainer}>{permissionsList}</div>
       <div className={css.buttonsContainer}>
         <Button
           variant="outline"
           className={css.backButton}
           buttonColor={buttonThemes.outline}
           onClick={onCloseModal}
         >
           Back
         </Button>
         <Button
           variant="filled"
           className={css.createRoleButton}
           buttonColor={buttonThemes.standard}
           onClick={onClickCreateRole}
         >
           {saveButtonContent}
         </Button>
       </div>
     </Modal>
   );
 }
 
 export default CreateRolesModal;