diff --git a/doc/source/whatsnew/v2.0.0.rst b/doc/source/whatsnew/v2.0.0.rst
index bde97f3714219..d8609737b8c7a 100644
--- a/doc/source/whatsnew/v2.0.0.rst
+++ b/doc/source/whatsnew/v2.0.0.rst
@@ -386,6 +386,7 @@ Removal of prior version deprecations/changes
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 - Removed deprecated :attr:`Timestamp.freq`, :attr:`Timestamp.freqstr` and argument ``freq`` from the :class:`Timestamp` constructor and :meth:`Timestamp.fromordinal` (:issue:`14146`)
 - Removed deprecated :class:`CategoricalBlock`, :meth:`Block.is_categorical`, require datetime64 and timedelta64 values to be wrapped in :class:`DatetimeArray` or :class:`TimedeltaArray` before passing to :meth:`Block.make_block_same_class`, require ``DatetimeTZBlock.values`` to have the correct ndim when passing to the :class:`BlockManager` constructor, and removed the "fastpath" keyword from the :class:`SingleBlockManager` constructor (:issue:`40226`, :issue:`40571`)
+- Removed deprecated global option ``use_inf_as_null`` in favor of ``use_inf_as_na`` (:issue:`17126`)
 - Removed deprecated module ``pandas.core.index`` (:issue:`30193`)
 - Removed deprecated alias ``pandas.core.tools.datetimes.to_time``, import the function directly from ``pandas.core.tools.times`` instead (:issue:`34145`)
 - Removed deprecated :meth:`Categorical.to_dense`, use ``np.asarray(cat)`` instead (:issue:`32639`)
diff --git a/pandas/core/config_init.py b/pandas/core/config_init.py
index b101b25a10a80..d1a52798360bd 100644
--- a/pandas/core/config_init.py
+++ b/pandas/core/config_init.py
@@ -458,12 +458,6 @@ def is_terminal() -> bool:
 with cf.config_prefix("mode"):
     cf.register_option("sim_interactive", False, tc_sim_interactive_doc)
 
-use_inf_as_null_doc = """
-: boolean
-    use_inf_as_null had been deprecated and will be removed in a future
-    version. Use `use_inf_as_na` instead.
-"""
-
 use_inf_as_na_doc = """
 : boolean
     True means treat None, NaN, INF, -INF as NA (old way),
@@ -483,14 +477,6 @@ def use_inf_as_na_cb(key) -> None:
 
 with cf.config_prefix("mode"):
     cf.register_option("use_inf_as_na", False, use_inf_as_na_doc, cb=use_inf_as_na_cb)
-    cf.register_option(
-        "use_inf_as_null", False, use_inf_as_null_doc, cb=use_inf_as_na_cb
-    )
-
-
-cf.deprecate_option(
-    "mode.use_inf_as_null", msg=use_inf_as_null_doc, rkey="mode.use_inf_as_na"
-)
 
 
 data_manager_doc = """
diff --git a/pandas/tests/series/test_missing.py b/pandas/tests/series/test_missing.py
index d956b2c3fcd42..3c0f962b90086 100644
--- a/pandas/tests/series/test_missing.py
+++ b/pandas/tests/series/test_missing.py
@@ -36,20 +36,6 @@ def test_isna_for_inf(self):
         tm.assert_series_equal(r, e)
         tm.assert_series_equal(dr, de)
 
-    @pytest.mark.parametrize(
-        "method, expected",
-        [
-            ["isna", Series([False, True, True, False])],
-            ["dropna", Series(["a", 1.0], index=[0, 3])],
-        ],
-    )
-    def test_isnull_for_inf_deprecated(self, method, expected):
-        # gh-17115
-        s = Series(["a", np.inf, np.nan, 1.0])
-        with pd.option_context("mode.use_inf_as_null", True):
-            result = getattr(s, method)()
-        tm.assert_series_equal(result, expected)
-
     def test_timedelta64_nan(self):
 
         td = Series([timedelta(days=i) for i in range(10)])