diff --git a/tildes/alembic/versions/e9bbc2929d9c_group_add_sidebar_markdown_html.py b/tildes/alembic/versions/e9bbc2929d9c_group_add_sidebar_markdown_html.py
new file mode 100644
index 0000000..f22a57b
--- /dev/null
+++ b/tildes/alembic/versions/e9bbc2929d9c_group_add_sidebar_markdown_html.py
@@ -0,0 +1,28 @@
+"""Group: add sidebar markdown/html
+
+Revision ID: e9bbc2929d9c
+Revises: 9b88cb0a7b2c
+Create Date: 2019-05-31 00:18:07.179045
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = "e9bbc2929d9c"
+down_revision = "9b88cb0a7b2c"
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    op.add_column("groups", sa.Column("sidebar_markdown", sa.Text(), nullable=True))
+    op.add_column(
+        "groups", sa.Column("sidebar_rendered_html", sa.Text(), nullable=True)
+    )
+
+
+def downgrade():
+    op.drop_column("groups", "sidebar_rendered_html")
+    op.drop_column("groups", "sidebar_markdown")
diff --git a/tildes/tildes/models/group/group.py b/tildes/tildes/models/group/group.py
index b915a08..ea60100 100644
--- a/tildes/tildes/models/group/group.py
+++ b/tildes/tildes/models/group/group.py
@@ -9,10 +9,12 @@ from typing import Any, List, Optional, Sequence, Tuple
 from pyramid.security import Allow, Authenticated, Deny, DENY_ALL, Everyone
 from sqlalchemy import Boolean, CheckConstraint, Column, Index, Integer, Text, TIMESTAMP
 from sqlalchemy.ext.hybrid import hybrid_property
+from sqlalchemy.orm import deferred
 from sqlalchemy.sql.expression import text
 from sqlalchemy_utils import Ltree, LtreeType
 
 from tildes.lib.database import ArrayOfLtree
+from tildes.lib.markdown import convert_markdown_to_safe_html
 from tildes.models import DatabaseModel
 from tildes.schemas.group import GroupSchema, SHORT_DESCRIPTION_MAX_LENGTH
 
@@ -45,6 +47,8 @@ class Group(DatabaseModel):
             name="short_description_length",
         ),
     )
+    _sidebar_markdown: str = deferred(Column("sidebar_markdown", Text))
+    sidebar_rendered_html: str = deferred(Column(Text))
     num_subscriptions: int = Column(Integer, nullable=False, server_default="0")
     is_admin_posting_only: bool = Column(
         Boolean, nullable=False, server_default="false"
@@ -70,6 +74,24 @@ class Group(DatabaseModel):
     def common_topic_tags(self, new_tags: List[str]) -> None:
         self._common_topic_tags = new_tags
 
+    @hybrid_property
+    def sidebar_markdown(self) -> str:
+        """Return the sidebar's markdown."""
+        return self._sidebar_markdown
+
+    @sidebar_markdown.setter  # type: ignore
+    def sidebar_markdown(self, new_markdown: str) -> None:
+        """Set the sidebar's markdown and render its HTML."""
+        if new_markdown == self.sidebar_markdown:
+            return
+
+        self._sidebar_markdown = new_markdown
+
+        if self._sidebar_markdown is not None:
+            self.sidebar_rendered_html = convert_markdown_to_safe_html(new_markdown)
+        else:
+            self.sidebar_rendered_html = None
+
     def __repr__(self) -> str:
         """Display the group's path and ID as its repr format."""
         return f"<Group {self.path} ({self.group_id})>"
diff --git a/tildes/tildes/schemas/group.py b/tildes/tildes/schemas/group.py
index ed00850..0c127e9 100644
--- a/tildes/tildes/schemas/group.py
+++ b/tildes/tildes/schemas/group.py
@@ -10,7 +10,7 @@ from marshmallow.exceptions import ValidationError
 from marshmallow.fields import DateTime
 import sqlalchemy_utils
 
-from tildes.schemas.fields import Ltree, SimpleString
+from tildes.schemas.fields import Ltree, Markdown, SimpleString
 
 
 # Validation regex for each individual "element" of a group path, encodes:
@@ -37,6 +37,7 @@ class GroupSchema(Schema):
     short_description = SimpleString(
         max_length=SHORT_DESCRIPTION_MAX_LENGTH, allow_none=True
     )
+    sidebar_markdown = Markdown(allow_none=True)
 
     @pre_load
     def prepare_path(self, data: dict) -> dict:
@@ -65,6 +66,18 @@ class GroupSchema(Schema):
             if not GROUP_PATH_ELEMENT_VALID_REGEX.match(element):
                 raise ValidationError("Path element %s is invalid" % element)
 
+    @pre_load
+    def prepare_sidebar_markdown(self, data: dict) -> dict:
+        """Prepare the sidebar_markdown value before it's validated."""
+        if "sidebar_markdown" not in data:
+            return data
+
+        # if the value is empty, convert it to None
+        if not data["sidebar_markdown"] or data["sidebar_markdown"].isspace():
+            data["sidebar_markdown"] = None
+
+        return data
+
     class Meta:
         """Always use strict checking so error handlers are invoked."""
 
diff --git a/tildes/tildes/templates/topic_listing.jinja2 b/tildes/tildes/templates/topic_listing.jinja2
index 1fdac49..f3703ac 100644
--- a/tildes/tildes/templates/topic_listing.jinja2
+++ b/tildes/tildes/templates/topic_listing.jinja2
@@ -220,6 +220,10 @@
     <a href="/~{{ group.path }}/new_topic" class="btn btn-primary">Post a new topic</a>
   {% endif %}
 
+  {% if group.sidebar_rendered_html %}
+    {{ group.sidebar_rendered_html|safe }}
+  {% endif %}
+
   {% if wiki_pages %}
     <ul class="nav">
       <li>Group wiki pages</li>