diff --git a/pandas/io/clipboard/__init__.py b/pandas/io/clipboard/__init__.py
index 4cc81a22a60a4..7d3dbaf6ee021 100644
--- a/pandas/io/clipboard/__init__.py
+++ b/pandas/io/clipboard/__init__.py
@@ -91,7 +91,7 @@ def __init__(self, message):
         super().__init__(message)
 
 
-def _stringifyText(text):
+def _stringifyText(text) -> str:
     acceptedTypes = (str, int, float, bool)
     if not isinstance(text, acceptedTypes):
         raise PyperclipException(
@@ -156,7 +156,7 @@ def copy_qt(text):
         cb = app.clipboard()
         cb.setText(text)
 
-    def paste_qt():
+    def paste_qt() -> str:
         cb = app.clipboard()
         return str(cb.text())
 
@@ -273,7 +273,7 @@ def copy_dev_clipboard(text):
         with open("/dev/clipboard", "wt") as fo:
             fo.write(text)
 
-    def paste_dev_clipboard():
+    def paste_dev_clipboard() -> str:
         with open("/dev/clipboard", "rt") as fo:
             content = fo.read()
         return content
@@ -286,7 +286,7 @@ class ClipboardUnavailable:
         def __call__(self, *args, **kwargs):
             raise PyperclipException(EXCEPT_MSG)
 
-        def __bool__(self):
+        def __bool__(self) -> bool:
             return False
 
     return ClipboardUnavailable(), ClipboardUnavailable()
@@ -650,7 +650,7 @@ def lazy_load_stub_paste():
     return paste()
 
 
-def is_available():
+def is_available() -> bool:
     return copy != lazy_load_stub_copy and paste != lazy_load_stub_paste