diff --git a/strings/camel_case_to_snake_case.py b/strings/camel_case_to_snake_case.py
new file mode 100644
index 000000000000..6a3057e92bae
--- /dev/null
+++ b/strings/camel_case_to_snake_case.py
@@ -0,0 +1,40 @@
+import re
+
+
+def camel_to_snake_case(input_str: str) -> str:
+    """
+    Transforms a camelCase or PascalCase given string to snake_case
+
+    >>> camel_to_snake_case("someRandomString")
+    'some_random_string'
+
+    >>> camel_to_snake_case("SomeRandomString")
+    'some_random_string'
+
+    >>> camel_to_snake_case("someRandomStringWithNumbers123")
+    'some_random_string_with_numbers_123'
+
+    >>> camel_to_snake_case("SomeRandomStringWithNumbers123")
+    'some_random_string_with_numbers_123'
+
+    >>> camel_to_snake_case(123)
+    Traceback (most recent call last):
+        ...
+    ValueError: Expected string as input, found <class 'int'>
+    """
+
+    if not isinstance(input_str, str):
+        msg = f"Expected string as input, found {type(input_str)}"
+        raise ValueError(msg)
+
+    # Use regular expression to split words on capital letters and numbers
+    words = re.findall(r"[A-Z][a-z]*|\d+|[a-z]+", input_str)
+
+    # Join the words with underscores and convert to lowercase
+    return "_".join(words).lower()
+
+
+if __name__ == "__main__":
+    from doctest import testmod
+
+    testmod()