diff --git a/Doc/library/cgi.rst b/Doc/library/cgi.rst
--- a/Doc/library/cgi.rst
+++ b/Doc/library/cgi.rst
@@ -152,16 +152,19 @@ return bytes)::
    if fileitem.file:
        # It's an uploaded file; count lines
        linecount = 0
        while True:
            line = fileitem.file.readline()
            if not line: break
            linecount = linecount + 1
 
+:class:`FieldStorage` objects also support being used in a :keyword:`with`
+statement, which will automatically close them when done.
+
 If an error is encountered when obtaining the contents of an uploaded file
 (for example, when the user interrupts the form submission by clicking on
 a Back or Cancel button) the :attr:`~FieldStorage.done` attribute of the
 object for the field will be set to the value -1.
 
 The file upload draft standard entertains the possibility of uploading multiple
 files from one field (using a recursive :mimetype:`multipart/\*` encoding).
 When this occurs, the item will be a dictionary-like :class:`FieldStorage` item.
@@ -177,16 +180,20 @@ actually be instances of the class :clas
 
 A form submitted via POST that also has a query string will contain both
 :class:`FieldStorage` and :class:`MiniFieldStorage` items.
 
 .. versionchanged:: 3.4
    The :attr:`~FieldStorage.file` attribute is automatically closed upon the
    garbage collection of the creating :class:`FieldStorage` instance.
 
+.. versionchanged:: 3.5
+   Added support for the context management protocol to the
+   :class:`FieldStorage` class.
+
 
 Higher Level Interface
 ----------------------
 
 The previous section explains how to read CGI form data using the
 :class:`FieldStorage` class.  This section describes a higher level interface
 which was added to this class to allow one to do it in a more readable and
 intuitive way.  The interface doesn't make the techniques described in previous
diff --git a/Doc/whatsnew/3.5.rst b/Doc/whatsnew/3.5.rst
--- a/Doc/whatsnew/3.5.rst
+++ b/Doc/whatsnew/3.5.rst
@@ -131,16 +131,22 @@ New Modules
 .. -----------
 
 * None yet.
 
 
 Improved Modules
 ================
 
+cgi
+---
+
+* :class:`FieldStorage` now supports the context management protocol.
+  (Contributed by Berker Peksag in :issue:`20289`.)
+
 code
 ----
 
 * The :func:`code.InteractiveInterpreter.showtraceback` method now prints
   the full chained traceback, just like the interactive interpreter.
   (Contributed by Claudiu.Popa in :issue:`17442`.)
 
 compileall
diff --git a/Lib/cgi.py b/Lib/cgi.py
--- a/Lib/cgi.py
+++ b/Lib/cgi.py
@@ -561,16 +561,22 @@ class FieldStorage:
             self.read_single()
 
     def __del__(self):
         try:
             self.file.close()
         except AttributeError:
             pass
 
+    def __enter__(self):
+        return self
+
+    def __exit__(self, *args):
+        self.file.close()
+
     def __repr__(self):
         """Return a printable representation."""
         return "FieldStorage(%r, %r, %r)" % (
                 self.name, self.filename, self.value)
 
     def __iter__(self):
         return iter(self.keys())
 
diff --git a/Lib/test/test_cgi.py b/Lib/test/test_cgi.py
--- a/Lib/test/test_cgi.py
+++ b/Lib/test/test_cgi.py
@@ -1,9 +1,9 @@
-from test.support import run_unittest, check_warnings
+from test.support import check_warnings
 import cgi
 import os
 import sys
 import tempfile
 import unittest
 import warnings
 from collections import namedtuple
 from io import StringIO, BytesIO
@@ -302,16 +302,27 @@ Content-Type: text/plain
         self.assertEqual(len(files), 2)
         expect = [{'name': None, 'filename': 'file1.txt', 'value': b'... contents of file1.txt ...'},
                   {'name': None, 'filename': 'file2.gif', 'value': b'...contents of file2.gif...'}]
         for x in range(len(files)):
             for k, exp in expect[x].items():
                 got = getattr(files[x], k)
                 self.assertEqual(got, exp)
 
+    def test_fieldstorage_as_context_manager(self):
+        fp = BytesIO(b'x' * 10)
+        env = {'REQUEST_METHOD': 'PUT'}
+        with cgi.FieldStorage(fp=fp, environ=env) as fs:
+            content = fs.file.read()
+            self.assertFalse(fs.file.closed)
+        self.assertTrue(fs.file.closed)
+        self.assertEqual(content, 'x' * 10)
+        with self.assertRaisesRegex(ValueError, 'I/O operation on closed file'):
+            fs.file.read()
+
     _qs_result = {
         'key1': 'value1',
         'key2': ['value2x', 'value2y'],
         'key3': 'value3',
         'key4': 'value4'
     }
     def testQSAndUrlEncode(self):
         data = "key2=value2x&key3=value3&key4=value4"
@@ -476,14 +487,10 @@ Content-Disposition: file; filename="fil
 Content-Type: image/gif
 Content-Transfer-Encoding: binary
 
 ...contents of file2.gif...
 --BbC04y--
 --AaB03x--
 """
 
-
-def test_main():
-    run_unittest(CgiTests)
-
 if __name__ == '__main__':
-    test_main()
+    unittest.main()