diff --git a/Doc/library/codecs.rst b/Doc/library/codecs.rst
index 9259ab10d5850b..059ed2c03acfa3 100644
--- a/Doc/library/codecs.rst
+++ b/Doc/library/codecs.rst
@@ -1155,7 +1155,7 @@ particular, the following variants typically exist:
 +-----------------+--------------------------------+--------------------------------+
 | cp857           | 857, IBM857                    | Turkish                        |
 +-----------------+--------------------------------+--------------------------------+
-| cp858           | 858, IBM858                    | Western Europe                 |
+| cp858           | 858, IBM00858                  | Western Europe                 |
 +-----------------+--------------------------------+--------------------------------+
 | cp860           | 860, IBM860                    | Portuguese                     |
 +-----------------+--------------------------------+--------------------------------+
@@ -1192,7 +1192,7 @@ particular, the following variants typically exist:
 |                 |                                |                                |
 |                 |                                | .. versionadded:: 3.4          |
 +-----------------+--------------------------------+--------------------------------+
-| cp1140          | ibm1140                        | Western Europe                 |
+| cp1140          | IBM01140                       | Western Europe                 |
 +-----------------+--------------------------------+--------------------------------+
 | cp1250          | windows-1250                   | Central and Eastern Europe     |
 +-----------------+--------------------------------+--------------------------------+
diff --git a/Lib/encodings/aliases.py b/Lib/encodings/aliases.py
index f4b1b8dd43f920..e5e50630f33d14 100644
--- a/Lib/encodings/aliases.py
+++ b/Lib/encodings/aliases.py
@@ -71,6 +71,10 @@
 
     # cp1140 codec
     '1140'               : 'cp1140',
+    'cp01140'            : 'cp1140',
+    'csibm01140'         : 'cp1140',
+    'ebcdic_us_37_euro'  : 'cp1140',
+    'ibm01140'           : 'cp1140',
     'ibm1140'            : 'cp1140',
 
     # cp1250 codec
@@ -159,8 +163,12 @@
 
     # cp858 codec
     '858'                : 'cp858',
+    'cp00858'            : 'cp858',
+    'csibm00858'         : 'cp858',
     'csibm858'           : 'cp858',
+    'ibm00858'           : 'cp858',
     'ibm858'             : 'cp858',
+    'pc_multilingual_850_euro' : 'cp858',
 
     # cp860 codec
     '860'                : 'cp860',
diff --git a/Misc/NEWS.d/next/Library/2026-05-13-23-18-39.gh-issue-149801.S_FfGr.rst b/Misc/NEWS.d/next/Library/2026-05-13-23-18-39.gh-issue-149801.S_FfGr.rst
new file mode 100644
index 00000000000000..f9e8538527d204
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2026-05-13-23-18-39.gh-issue-149801.S_FfGr.rst
@@ -0,0 +1,2 @@
+Add IANA registered names and aliases with leading zeros before number (like
+IBM00858, CP00858, IBM01140, CP01140) for corresponding codecs.