diff --git a/datasette/templates/query.html b/datasette/templates/query.html
index 2fb461a1..b23c67d8 100644
--- a/datasette/templates/query.html
+++ b/datasette/templates/query.html
@@ -26,7 +26,7 @@
 {% block description_source_license %}{% include "_description_source_license.html" %}{% endblock %}
 
 <form class="sql" action="/{{ database }}-{{ database_hash }}{% if canned_query %}/{{ canned_query }}{% endif %}" method="get">
-    <h3>Custom SQL query{% if rows %} returning {% if truncated %}more than {% endif %}{{ "{:,}".format(rows|length) }} row{% if rows|length == 1 %}{% else %}s{% endif %}{% endif %}</h3>
+    <h3>Custom SQL query{% if display_rows %} returning {% if truncated %}more than {% endif %}{{ "{:,}".format(display_rows|length) }} row{% if display_rows|length == 1 %}{% else %}s{% endif %}{% endif %}</h3>
     {% if editable and config.allow_sql %}
         <p><textarea name="sql">{% if query and query.sql %}{{ query.sql }}{% else %}select * from {{ tables[0].name|escape_sqlite }}{% endif %}</textarea></p>
     {% else %}
@@ -41,7 +41,7 @@
     <p><input type="submit" value="Run SQL"></p>
 </form>
 
-{% if rows %}
+{% if display_rows %}
 <p class="export-links">This data as <a href="{{ url_json }}">JSON</a>, <a href="{{ url_csv }}">CSV</a></p>
 <table class="rows-and-columns">
     <thead>
@@ -50,7 +50,7 @@
         </tr>
     </thead>
     <tbody>
-    {% for row in rows %}
+    {% for row in display_rows %}
         <tr>
             {% for column, td in zip(columns, row) %}
                 <td class="col-{{ column|to_css_class }}">{% if td == None %}{{ "&nbsp;"|safe }}{% else %}{{ td }}{% endif %}</td>
diff --git a/datasette/views/base.py b/datasette/views/base.py
index 3da3793c..45bc8183 100644
--- a/datasette/views/base.py
+++ b/datasette/views/base.py
@@ -6,6 +6,7 @@ import sqlite3
 import time
 import urllib
 
+import jinja2
 import pint
 from sanic import response
 from sanic.exceptions import NotFound
@@ -17,6 +18,7 @@ from datasette.utils import (
     InterruptedError,
     InvalidSql,
     LimitedWriter,
+    is_url,
     path_from_row_pks,
     path_with_added_args,
     path_with_format,
@@ -485,21 +487,40 @@ class BaseView(RenderMixin):
                 ),
             )
 
+        async def extra_template():
+            display_rows = []
+            for row in results.rows:
+                display_row = []
+                for value in row:
+                    display_value = value
+                    if value in ("", None):
+                        display_value = jinja2.Markup("&nbsp;")
+                    elif is_url(str(value).strip()):
+                        display_value = jinja2.Markup(
+                            '<a href="{url}">{url}</a>'.format(
+                                url=jinja2.escape(value.strip())
+                            )
+                        )
+                    display_row.append(display_value)
+                display_rows.append(display_row)
+            return {
+                "display_rows": display_rows,
+                "database_hash": hash,
+                "custom_sql": True,
+                "named_parameter_values": named_parameter_values,
+                "editable": editable,
+                "canned_query": canned_query,
+                "metadata": metadata,
+                "config": self.ds.config,
+            }
+
         return {
             "database": name,
             "rows": results.rows,
             "truncated": results.truncated,
             "columns": columns,
             "query": {"sql": sql, "params": params},
-        }, {
-            "database_hash": hash,
-            "custom_sql": True,
-            "named_parameter_values": named_parameter_values,
-            "editable": editable,
-            "canned_query": canned_query,
-            "metadata": metadata,
-            "config": self.ds.config,
-        }, templates
+        }, extra_template, templates
 
 
 def convert_specific_columns_to_json(rows, columns, json_cols):
diff --git a/tests/test_html.py b/tests/test_html.py
index 0b920fff..5f59f61a 100644
--- a/tests/test_html.py
+++ b/tests/test_html.py
@@ -793,3 +793,17 @@ def test_advanced_export_box(app_client, path, has_object, has_stream, has_expan
     # "expand labels" option
     if has_expand:
         assert "expand labels" in str(div)
+
+
+def test_urlify_custom_queries(app_client):
+    path = "/fixtures?" + urllib.parse.urlencode({
+        "sql": "select ('https://twitter.com/' || 'simonw') as user_url;"
+    })
+    response = app_client.get(path)
+    assert response.status == 200
+    soup = Soup(response.body, "html.parser")
+    assert '''<td class="col-user_url">
+ <a href="https://twitter.com/simonw">
+  https://twitter.com/simonw
+ </a>
+</td>''' == soup.find("td", {"class": "col-user_url"}).prettify().strip()