diff --git a/gateway/platforms/telegram.py b/gateway/platforms/telegram.py
index dd4632e13f..9587298b4e 100644
--- a/gateway/platforms/telegram.py
+++ b/gateway/platforms/telegram.py
@@ -79,8 +79,8 @@ def _escape_mdv2(text: str) -> str:
 def _strip_mdv2(text: str) -> str:
     """Strip MarkdownV2 escape backslashes to produce clean plain text.
 
-    Also removes MarkdownV2 bold markers (*text* -> text) so the fallback
-    doesn't show stray asterisks from header/bold conversion.
+    Also removes MarkdownV2 formatting markers so the fallback
+    doesn't show stray syntax characters from format_message conversion.
     """
     # Remove escape backslashes before special characters
     cleaned = re.sub(r'\\([_*\[\]()~`>#\+\-=|{}.!\\])', r'\1', text)
@@ -89,6 +89,10 @@ def _strip_mdv2(text: str) -> str:
     # Remove MarkdownV2 italic markers that format_message converted from *italic*
     # Use word boundary (\b) to avoid breaking snake_case like my_variable_name
     cleaned = re.sub(r'(?<!\w)_([^_]+)_(?!\w)', r'\1', cleaned)
+    # Remove MarkdownV2 strikethrough markers (~text~ → text)
+    cleaned = re.sub(r'~([^~]+)~', r'\1', cleaned)
+    # Remove MarkdownV2 spoiler markers (||text|| → text)
+    cleaned = re.sub(r'\|\|([^|]+)\|\|', r'\1', cleaned)
     return cleaned
 
 
@@ -848,10 +852,32 @@ class TelegramAdapter(BasePlatformAdapter):
             text,
         )
 
-        # 7) Escape remaining special characters in plain text
+        # 7) Convert strikethrough: ~~text~~ → ~text~ (MarkdownV2)
+        text = re.sub(
+            r'~~(.+?)~~',
+            lambda m: _ph(f'~{_escape_mdv2(m.group(1))}~'),
+            text,
+        )
+
+        # 8) Convert spoiler: ||text|| → ||text|| (protect from | escaping)
+        text = re.sub(
+            r'\|\|(.+?)\|\|',
+            lambda m: _ph(f'||{_escape_mdv2(m.group(1))}||'),
+            text,
+        )
+
+        # 9) Convert blockquotes: > at line start → protect > from escaping
+        text = re.sub(
+            r'^(>{1,3}) (.+)$',
+            lambda m: _ph(m.group(1) + ' ' + _escape_mdv2(m.group(2))),
+            text,
+            flags=re.MULTILINE,
+        )
+
+        # 10) Escape remaining special characters in plain text
         text = _escape_mdv2(text)
 
-        # 8) Restore placeholders in reverse insertion order so that
+        # 11) Restore placeholders in reverse insertion order so that
         #    nested references (a placeholder inside another) resolve correctly.
         for key in reversed(list(placeholders.keys())):
             text = text.replace(key, placeholders[key])
diff --git a/tests/gateway/test_telegram_format.py b/tests/gateway/test_telegram_format.py
index bc840da90c..446a3e1b96 100644
--- a/tests/gateway/test_telegram_format.py
+++ b/tests/gateway/test_telegram_format.py
@@ -320,6 +320,95 @@ class TestItalicNewlineBug:
         assert "_italic_" in result
 
 
+# =========================================================================
+# format_message - strikethrough
+# =========================================================================
+
+
+class TestFormatMessageStrikethrough:
+    def test_strikethrough_converted(self, adapter):
+        result = adapter.format_message("This is ~~deleted~~ text")
+        assert "~deleted~" in result
+        assert "~~" not in result
+
+    def test_strikethrough_with_special_chars(self, adapter):
+        result = adapter.format_message("~~hello.world!~~")
+        assert "~hello\\.world\\!~" in result
+
+    def test_strikethrough_in_code_not_converted(self, adapter):
+        result = adapter.format_message("`~~not struck~~`")
+        assert "`~~not struck~~`" in result
+
+    def test_strikethrough_with_bold(self, adapter):
+        result = adapter.format_message("**bold** and ~~struck~~")
+        assert "*bold*" in result
+        assert "~struck~" in result
+
+
+# =========================================================================
+# format_message - spoiler
+# =========================================================================
+
+
+class TestFormatMessageSpoiler:
+    def test_spoiler_converted(self, adapter):
+        result = adapter.format_message("This is ||hidden|| text")
+        assert "||hidden||" in result
+
+    def test_spoiler_with_special_chars(self, adapter):
+        result = adapter.format_message("||hello.world!||")
+        assert "||hello\\.world\\!||" in result
+
+    def test_spoiler_in_code_not_converted(self, adapter):
+        result = adapter.format_message("`||not spoiler||`")
+        assert "`||not spoiler||`" in result
+
+    def test_spoiler_pipes_not_escaped(self, adapter):
+        """The || delimiters must not be escaped as \\|\\|."""
+        result = adapter.format_message("||secret||")
+        assert "\\|\\|" not in result
+        assert "||secret||" in result
+
+
+# =========================================================================
+# format_message - blockquote
+# =========================================================================
+
+
+class TestFormatMessageBlockquote:
+    def test_blockquote_converted(self, adapter):
+        result = adapter.format_message("> This is a quote")
+        assert "> This is a quote" in result
+        # > must NOT be escaped
+        assert "\\>" not in result
+
+    def test_blockquote_with_special_chars(self, adapter):
+        result = adapter.format_message("> Hello (world)!")
+        assert "> Hello \\(world\\)\\!" in result
+        assert "\\>" not in result
+
+    def test_blockquote_multiline(self, adapter):
+        text = "> Line one\n> Line two"
+        result = adapter.format_message(text)
+        assert "> Line one" in result
+        assert "> Line two" in result
+        assert "\\>" not in result
+
+    def test_blockquote_in_code_not_converted(self, adapter):
+        result = adapter.format_message("```\n> not a quote\n```")
+        assert "> not a quote" in result
+
+    def test_nested_blockquote(self, adapter):
+        result = adapter.format_message(">> Nested quote")
+        assert ">> Nested quote" in result
+        assert "\\>" not in result
+
+    def test_gt_in_middle_of_line_still_escaped(self, adapter):
+        """Only > at line start is a blockquote; mid-line > should be escaped."""
+        result = adapter.format_message("5 > 3")
+        assert "\\>" in result
+
+
 # =========================================================================
 # format_message - mixed/complex
 # =========================================================================
@@ -418,6 +507,12 @@ class TestStripMdv2:
     def test_empty_string(self):
         assert _strip_mdv2("") == ""
 
+    def test_removes_strikethrough_markers(self):
+        assert _strip_mdv2("~struck text~") == "struck text"
+
+    def test_removes_spoiler_markers(self):
+        assert _strip_mdv2("||hidden text||") == "hidden text"
+
 
 @pytest.mark.asyncio
 async def test_send_escapes_chunk_indicator_for_markdownv2(adapter):