diff --git a/CHANGELOG.md b/CHANGELOG.md
index cd6c12ac01..fd987eae6c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -25,7 +25,7 @@ and this project adheres to [Semantic Versioning](https://semver.org).
 
 ### Fixed
 
-- Nothing yet.
+- Add support for `<s>` tag when converting HTML to RichText. [Issue #4223](https://github.com/PHPOffice/PhpSpreadsheet/issues/4223) [PR #4224](https://github.com/PHPOffice/PhpSpreadsheet/pull/4224)
 
 ## 2024-11-10 - 3.4.0
 
diff --git a/src/PhpSpreadsheet/Helper/Html.php b/src/PhpSpreadsheet/Helper/Html.php
index e690ae6525..f9fc6e3dc2 100644
--- a/src/PhpSpreadsheet/Helper/Html.php
+++ b/src/PhpSpreadsheet/Helper/Html.php
@@ -561,6 +561,7 @@ class Html
         'u' => [self::class, 'startUnderlineTag'],
         'ins' => [self::class, 'startUnderlineTag'],
         'del' => [self::class, 'startStrikethruTag'],
+        's' => [self::class, 'startStrikethruTag'],
         'sup' => [self::class, 'startSuperscriptTag'],
         'sub' => [self::class, 'startSubscriptTag'],
     ];
@@ -575,6 +576,7 @@ class Html
         'u' => [self::class, 'endUnderlineTag'],
         'ins' => [self::class, 'endUnderlineTag'],
         'del' => [self::class, 'endStrikethruTag'],
+        's' => [self::class, 'endStrikethruTag'],
         'sup' => [self::class, 'endSuperscriptTag'],
         'sub' => [self::class, 'endSubscriptTag'],
         'br' => [self::class, 'breakTag'],
diff --git a/tests/PhpSpreadsheetTests/Helper/HtmlTest.php b/tests/PhpSpreadsheetTests/Helper/HtmlTest.php
index 784eb4c551..26f22847a1 100644
--- a/tests/PhpSpreadsheetTests/Helper/HtmlTest.php
+++ b/tests/PhpSpreadsheetTests/Helper/HtmlTest.php
@@ -48,4 +48,26 @@ public function testLiTag(): void
 
         self::assertSame($expected, $actual->getPlainText());
     }
+
+    public function testSTag(): void
+    {
+        $html = new Html();
+        $input = 'Hello <s>test</s>world';
+        $richText = $html->toRichTextObject($input);
+        $elements = $richText->getRichTextElements();
+
+        self::assertSame(count($elements), 3);
+
+        self::assertSame($elements[0]->getText(), 'Hello ');
+        self::assertNotNull($elements[0]->getFont());
+        self::assertFalse($elements[0]->getFont()->getStrikethrough());
+
+        self::assertSame($elements[1]->getText(), 'test');
+        self::assertNotNull($elements[1]->getFont());
+        self::assertTrue($elements[1]->getFont()->getStrikethrough());
+
+        self::assertSame($elements[2]->getText(), 'world');
+        self::assertNotNull($elements[2]->getFont());
+        self::assertFalse($elements[2]->getFont()->getStrikethrough());
+    }
 }