diff --git a/pandas/_libs/tslibs/parsing.pyx b/pandas/_libs/tslibs/parsing.pyx
index cfa16df367bce..c98c6850d10c5 100644
--- a/pandas/_libs/tslibs/parsing.pyx
+++ b/pandas/_libs/tslibs/parsing.pyx
@@ -892,6 +892,8 @@ def guess_datetime_format(
     if not isinstance(dt_str, str):
         return None
 
+    valid_am_pm = ['am', 'pm', 'a', 'p']
+
     day_attribute_and_format = (('day',), '%d', 2)
 
     # attr name, format, padding (if any)
@@ -947,6 +949,11 @@ def guess_datetime_format(
                     found_attrs.update(attrs)
                     break
 
+    # Final formatting is required if the dt_string contains AM/PM.
+    if tokens[i].lower() in valid_am_pm:
+        format_guess = ["%I" if guess == "%H" else guess for guess in format_guess]
+        format_guess[i] = "%p"
+
     # Only consider it a valid guess if we have a year, month and day
     if len({'year', 'month', 'day'} & found_attrs) != 3:
         return None
diff --git a/pandas/tests/tools/test_to_datetime.py b/pandas/tests/tools/test_to_datetime.py
index 469a5caf7d694..7e80c166efc7e 100644
--- a/pandas/tests/tools/test_to_datetime.py
+++ b/pandas/tests/tools/test_to_datetime.py
@@ -1965,6 +1965,41 @@ def test_to_datetime_infer_datetime_format_consistent_format(self, cache):
             tm.assert_series_equal(with_format, no_infer)
             tm.assert_series_equal(no_infer, yes_infer)
 
+    @pytest.mark.parametrize("cache", [True, False])
+    @pytest.mark.parametrize("errors", ["ignore", "coerce", "raise"])
+    def test_to_datetime_infer_datetime_consistent_formats_error_types(
+        self, cache, errors
+    ):
+        # GH#43414
+        s = Series(date_range("20000101", periods=50, freq="H"))
+        begin_timerange_condition = s.dt.hour >= 7
+        end_timerange_condition = s.dt.hour <= 13
+        s = s.loc[begin_timerange_condition & end_timerange_condition]
+
+        test_formats = [
+            "%m-%d-%Y",
+            "%m/%d/%Y %H:%M:%S.%f",
+            "%m/%d/%Y %I:%M:%S%p",
+            "%m/%d/%Y %I:%M:%S %p",
+            "%Y-%m-%dT%H:%M:%S.%f",
+            "%Y-%m-%dT%I:%M:%S%p",
+            "%Y-%m-%dT%I:%M:%S %p",
+            "%Y-%m-%d %H:%M:%S.%f",
+            "%Y-%m-%d %I:%M:%S%p",
+            "%Y-%m-%d %I:%M:%S %p",
+        ]
+
+        for test_format in test_formats:
+            s_as_dt_strings = s.apply(lambda x: x.strftime(test_format))
+
+            explicit_format = to_datetime(
+                s_as_dt_strings, errors=errors, format=test_format, cache=cache
+            )
+            inferred_format = to_datetime(
+                s_as_dt_strings, errors=errors, infer_datetime_format=True, cache=cache
+            )
+            tm.assert_series_equal(explicit_format, inferred_format)
+
     @pytest.mark.parametrize("cache", [True, False])
     def test_to_datetime_infer_datetime_format_inconsistent_format(self, cache):
         s = Series(