diff --git a/app/models/support.py b/app/models/support.py
index cf694df..47fdaf5 100644
--- a/app/models/support.py
+++ b/app/models/support.py
@@ -69,6 +69,11 @@ class SupportKnowledge(db.Model):
     title      = db.Column(db.String(200), nullable=False)
     body       = db.Column(db.Text, nullable=False)
     active     = db.Column(db.Boolean, default=True, nullable=False)
+    # MT-19 — admin-controlled ordering. Entries are injected into the support
+    # chat's system prompt in this order, so a low sort_order is how an admin
+    # promotes the guidance the assistant should reach for first. Ties break on
+    # id, keeping the order stable.
+    sort_order = db.Column(db.Integer, nullable=False, default=0)
     created_by = db.Column(db.Integer, db.ForeignKey('users.id', ondelete='SET NULL'), nullable=True)
     created_at = db.Column(db.DateTime, default=now_eastern, nullable=False)
     updated_at = db.Column(db.DateTime, default=now_eastern, nullable=False)
diff --git a/app/routes/support.py b/app/routes/support.py
index 59c438b..50d91d1 100644
--- a/app/routes/support.py
+++ b/app/routes/support.py
@@ -91,7 +91,9 @@ FAQS = [
 def _system_prompt_with_kb():
     """Return the Groq system prompt, appending active knowledge base entries."""
     try:
-        entries = SupportKnowledge.query.filter_by(active=True).order_by(SupportKnowledge.id).all()
+        entries = (SupportKnowledge.query.filter_by(active=True)
+                   .order_by(SupportKnowledge.sort_order.asc(),
+                             SupportKnowledge.id.asc()).all())
     except Exception:
         return _SYSTEM_PROMPT
     if not entries:
@@ -516,10 +518,31 @@ def admin_conversation_detail(session_id):
 @login_required
 @supervisor_required
 def admin_knowledge():
-    entries = SupportKnowledge.query.order_by(SupportKnowledge.created_at.desc()).all()
+    # Same order the chat prompt uses, so the admin list shows the real
+    # priority rather than a different one.
+    entries = (SupportKnowledge.query
+               .order_by(SupportKnowledge.sort_order.asc(),
+                         SupportKnowledge.id.asc()).all())
     return render_template('support/admin_knowledge.html', entries=entries)
 
 
+def _parse_sort_order(raw, fallback=0):
+    """Coerce a submitted sort_order to a sane int.
+
+    The column is NOT NULL, so a blank or non-numeric field must not reach the
+    DB. Clamped to 0..9999 to match the range ST validates, and falls back to
+    the existing value on edit so a blank field means "leave it alone" rather
+    than silently resetting the entry to the top.
+    """
+    raw = (raw or '').strip()
+    if not raw:
+        return fallback
+    try:
+        return max(0, min(9999, int(raw)))
+    except (TypeError, ValueError):
+        return fallback
+
+
 @bp.route('/admin/knowledge/add', methods=['POST'])
 @login_required
 @supervisor_required
@@ -534,6 +557,7 @@ def admin_knowledge_add():
         title      = title,
         body       = body,
         active     = True,
+        sort_order = _parse_sort_order(request.form.get('sort_order')),
         created_by = current_user.id,
         created_at = now_eastern(),
         updated_at = now_eastern(),
@@ -561,6 +585,8 @@ def admin_knowledge_edit(entry_id):
             return redirect(url_for('support.admin_knowledge_edit', entry_id=entry_id))
         entry.title      = title
         entry.body       = body
+        entry.sort_order = _parse_sort_order(request.form.get('sort_order'),
+                                             entry.sort_order)
         entry.updated_at = now_eastern()
         db.session.commit()
         log_action(ACTION_UPDATE, 'SupportKnowledge', entry.id, title[:60], 'edited')
diff --git a/app/templates/support/admin_knowledge.html b/app/templates/support/admin_knowledge.html
index 16e9150..7a91f7a 100644
--- a/app/templates/support/admin_knowledge.html
+++ b/app/templates/support/admin_knowledge.html
@@ -34,6 +34,12 @@
                   placeholder="Add facts, FAQs, or instructions the AI should know about this customer's account…"></textarea>
         <div class="form-text">Keep entries focused and factual. Combined active entries are capped at 6,000 characters.</div>
       </div>
+      <div class="mb-3" style="max-width:200px;">
+        <label class="form-label fw-semibold">Sort Order</label>
+        <input type="number" name="sort_order" class="form-control"
+               min="0" max="9999" step="1" value="0">
+        <div class="form-text">Lower numbers are sent to the assistant first. Leave at 0 unless an entry should take priority.</div>
+      </div>
       <button type="submit" class="btn btn-primary btn-sm">
         <i class="bi bi-plus me-1"></i>Add Entry
       </button>
@@ -54,6 +60,7 @@
       <div class="d-flex justify-content-between align-items-start">
         <div class="flex-grow-1 me-3">
           <div class="d-flex align-items-center gap-2 mb-1">
+            <span class="badge bg-light text-dark border" title="Sort order">#{{ entry.sort_order }}</span>
             <span class="fw-semibold">{{ entry.title }}</span>
             {% if entry.active %}
             <span class="badge bg-success">Active</span>
diff --git a/app/templates/support/admin_knowledge_edit.html b/app/templates/support/admin_knowledge_edit.html
index d7addec..12ca0e9 100644
--- a/app/templates/support/admin_knowledge_edit.html
+++ b/app/templates/support/admin_knowledge_edit.html
@@ -23,6 +23,12 @@
         <textarea name="body" class="form-control" rows="8" required>{{ entry.body }}</textarea>
         <div class="form-text">Combined active entries are capped at 6,000 characters in the AI prompt.</div>
       </div>
+      <div class="mb-3" style="max-width:200px;">
+        <label class="form-label fw-semibold">Sort Order</label>
+        <input type="number" name="sort_order" class="form-control"
+               min="0" max="9999" step="1" value="{{ entry.sort_order }}">
+        <div class="form-text">Lower numbers are sent to the assistant first. Leave at 0 unless an entry should take priority.</div>
+      </div>
       <div class="d-flex gap-2">
         <button type="submit" class="btn btn-primary">
           <i class="bi bi-check-lg me-1"></i>Save Changes
diff --git a/migrations/versions/phase53_knowledge_sort_order.py b/migrations/versions/phase53_knowledge_sort_order.py
new file mode 100644
index 0000000..7c0e0c4
--- /dev/null
+++ b/migrations/versions/phase53_knowledge_sort_order.py
@@ -0,0 +1,69 @@
+"""phase53 — admin-controlled ordering for support knowledge entries
+
+Adds to `support_knowledge`:
+
+    sort_order  INT NOT NULL DEFAULT 0
+
+Knowledge entries are injected into the support chat's Groq system prompt, and
+the combined text is capped, so the ORDER entries appear in decides which
+guidance the assistant reaches for first and which is truncated away. Before
+this the order was `id` — i.e. whenever the entry happened to be created — with
+no way for an admin to promote an important entry short of deleting and
+re-adding it.
+
+Ordering is `sort_order ASC, id ASC` everywhere it is read, so ties break
+deterministically and existing entries (all defaulting to 0) keep their current
+relative order on upgrade. Nothing is reshuffled by running this.
+
+Uses an INFORMATION_SCHEMA existence check — safe to re-run.
+"""
+
+revision      = 'phase53_knowledge_sort_order'
+down_revision = 'phase52_user_ui_theme'
+branch_labels = None
+depends_on    = None
+
+from alembic import op
+import sqlalchemy as sa
+
+
+def _column_exists(conn, table, column):
+    return conn.execute(sa.text(
+        "SELECT COUNT(*) FROM INFORMATION_SCHEMA.COLUMNS "
+        "WHERE TABLE_SCHEMA = DATABASE() "
+        "AND TABLE_NAME = :t AND COLUMN_NAME = :c"
+    ), {"t": table, "c": column}).scalar() > 0
+
+
+def _table_exists(conn, table):
+    return conn.execute(sa.text(
+        "SELECT COUNT(*) FROM INFORMATION_SCHEMA.TABLES "
+        "WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = :t"
+    ), {"t": table}).scalar() > 0
+
+
+def upgrade():
+    bind = op.get_bind()
+    # Guarded on the table too: support_knowledge arrived in phase40, and a
+    # tenant provisioned from an older baseline could reach this revision
+    # without it.
+    if not _table_exists(bind, 'support_knowledge'):
+        return
+    if not _column_exists(bind, 'support_knowledge', 'sort_order'):
+        op.execute(sa.text(
+            "ALTER TABLE support_knowledge "
+            "ADD COLUMN sort_order INT NOT NULL DEFAULT 0"
+        ))
+    # Idempotent repair only — never resets a deliberate ordering.
+    op.execute(sa.text(
+        "UPDATE support_knowledge SET sort_order = 0 WHERE sort_order IS NULL"
+    ))
+
+
+def downgrade():
+    bind = op.get_bind()
+    if (_table_exists(bind, 'support_knowledge')
+            and _column_exists(bind, 'support_knowledge', 'sort_order')):
+        op.execute(sa.text(
+            "ALTER TABLE support_knowledge DROP COLUMN sort_order"
+        ))
diff --git a/tests/test_knowledge_sort_order.py b/tests/test_knowledge_sort_order.py
new file mode 100644
index 0000000..edffda2
--- /dev/null
+++ b/tests/test_knowledge_sort_order.py
@@ -0,0 +1,161 @@
+"""
+tests/test_knowledge_sort_order.py
+----------------------------------
+Behaviour tests for MT-19 — admin-controlled ordering of support knowledge.
+
+Knowledge entries are injected into the support chat's Groq system prompt and
+the combined text is capped, so ORDER decides which guidance the assistant
+reaches for first and which gets truncated away. These tests pin that the
+column actually drives the prompt, not just the admin table.
+"""
+
+import pytest
+
+
+@pytest.fixture
+def client(app):
+    with app.app_context():
+        from app import db
+        from app.models import inspector_assignment  # noqa: F401
+        db.drop_all()
+        db.create_all()
+        yield app.test_client()
+        db.session.remove()
+
+
+def _user(username, role):
+    from app import db
+    from app.models.user import User
+    u = User(username=username, full_name=username.title(), role=role,
+             email=f'{username}@example.com', active=True)
+    u.set_password('pw-correct1')
+    db.session.add(u)
+    db.session.commit()
+    return u
+
+
+def _login(client, user):
+    resp = client.post('/auth/login',
+                       data={'username': user.username, 'password': 'pw-correct1'},
+                       follow_redirects=True)
+    assert 'Login - ' not in resp.get_data(as_text=True), 'login failed'
+    return resp
+
+
+def _kb(title, body, sort_order=0, active=True):
+    from app import db
+    from app.models.support import SupportKnowledge
+    from app.utils.time_utils import now_eastern
+    e = SupportKnowledge(title=title, body=body, active=active,
+                         sort_order=sort_order,
+                         created_at=now_eastern(), updated_at=now_eastern())
+    db.session.add(e)
+    db.session.commit()
+    return e
+
+
+def test_default_sort_order_is_zero(client):
+    from app import db
+    from app.models.support import SupportKnowledge
+    from app.utils.time_utils import now_eastern
+    e = SupportKnowledge(title='T', body='B', active=True,
+                         created_at=now_eastern(), updated_at=now_eastern())
+    db.session.add(e)
+    db.session.commit()
+    assert e.sort_order == 0
+
+
+def test_sort_order_drives_the_chat_prompt(client):
+    """The behaviour this phase exists for: a low sort_order promotes an entry
+    in the text handed to the assistant, regardless of creation order."""
+    from app.routes.support import _system_prompt_with_kb
+
+    _kb('Created First', 'AAA-FIRST', sort_order=10)
+    _kb('Created Second', 'ZZZ-SECOND', sort_order=1)
+
+    prompt = _system_prompt_with_kb()
+    assert prompt.index('ZZZ-SECOND') < prompt.index('AAA-FIRST'), (
+        'sort_order did not reorder the prompt')
+
+
+def test_ties_break_on_id_so_order_is_stable(client):
+    from app.routes.support import _system_prompt_with_kb
+
+    _kb('Alpha', 'AAA-ALPHA', sort_order=5)
+    _kb('Beta', 'BBB-BETA', sort_order=5)
+
+    prompt = _system_prompt_with_kb()
+    assert prompt.index('AAA-ALPHA') < prompt.index('BBB-BETA')
+
+
+def test_inactive_entries_stay_out_of_the_prompt(client):
+    """Ordering must not have widened what reaches the assistant."""
+    from app.routes.support import _system_prompt_with_kb
+
+    _kb('Live', 'AAA-LIVE', sort_order=9)
+    _kb('Disabled', 'ZZZ-DISABLED', sort_order=0, active=False)
+
+    prompt = _system_prompt_with_kb()
+    assert 'AAA-LIVE' in prompt
+    assert 'ZZZ-DISABLED' not in prompt
+
+
+def test_admin_can_set_sort_order_on_add(client):
+    from app.models.support import SupportKnowledge
+
+    admin = _user('ada', 'admin')
+    _login(client, admin)
+    client.post('/support/admin/knowledge/add',
+                data={'title': 'Priority', 'body': 'Body text', 'sort_order': '3'},
+                follow_redirects=True)
+
+    entry = SupportKnowledge.query.filter_by(title='Priority').first()
+    assert entry is not None
+    assert entry.sort_order == 3
+
+
+def test_blank_sort_order_on_edit_keeps_the_existing_value(client):
+    """The column is NOT NULL and blank must mean 'leave it alone', not
+    'silently promote this entry to the top'."""
+    from app.models.support import SupportKnowledge
+
+    admin = _user('ada', 'admin')
+    entry = _kb('Keep', 'Body', sort_order=7)
+    _login(client, admin)
+
+    client.post(f'/support/admin/knowledge/{entry.id}/edit',
+                data={'title': 'Keep', 'body': 'Body', 'sort_order': ''},
+                follow_redirects=True)
+
+    from app import db
+    assert db.session.get(SupportKnowledge, entry.id).sort_order == 7
+
+
+@pytest.mark.parametrize('raw,expected', [
+    ('abc', 0),        # non-numeric
+    ('-5', 0),         # clamped low
+    ('99999', 9999),   # clamped high
+])
+def test_bad_sort_order_never_reaches_a_not_null_column(client, raw, expected):
+    from app.models.support import SupportKnowledge
+
+    admin = _user('ada', 'admin')
+    _login(client, admin)
+    client.post('/support/admin/knowledge/add',
+                data={'title': f'E{raw}', 'body': 'B', 'sort_order': raw},
+                follow_redirects=True)
+
+    entry = SupportKnowledge.query.filter_by(title=f'E{raw}').first()
+    assert entry is not None, 'entry was rejected instead of coerced'
+    assert entry.sort_order == expected
+
+
+def test_admin_list_orders_the_same_way_as_the_prompt(client):
+    """The admin must see the real priority, not a different order."""
+    admin = _user('ada', 'admin')
+    _kb('Zebra Entry', 'B', sort_order=1)
+    _kb('Apple Entry', 'B', sort_order=9)
+    _login(client, admin)
+
+    body = client.get('/support/admin/knowledge').get_data(as_text=True)
+    assert body.index('Zebra Entry') < body.index('Apple Entry')