diff --git a/DIRECTORY.md b/DIRECTORY.md
index 36acb3b97f1e..0e84558ba580 100644
--- a/DIRECTORY.md
+++ b/DIRECTORY.md
@@ -189,6 +189,7 @@
     * [Find Triplets With 0 Sum](data_structures/arrays/find_triplets_with_0_sum.py)
     * [Index 2D Array In 1D](data_structures/arrays/index_2d_array_in_1d.py)
     * [Kth Largest Element](data_structures/arrays/kth_largest_element.py)
+    * [Maximum Subarray Sum](data_structures/arrays/maximum_subarray_sum.py)
     * [Median Two Array](data_structures/arrays/median_two_array.py)
     * [Monotonic Array](data_structures/arrays/monotonic_array.py)
     * [Pairs With Given Sum](data_structures/arrays/pairs_with_given_sum.py)
diff --git a/data_structures/arrays/maximum_subarray_sum.py b/data_structures/arrays/maximum_subarray_sum.py
new file mode 100644
index 000000000000..9bfa8948c0a1
--- /dev/null
+++ b/data_structures/arrays/maximum_subarray_sum.py
@@ -0,0 +1,34 @@
+def max_subarray_sum(arr: list[int]) -> int:
+    """
+    Find the maximum sum of a subarray.
+
+    Args:
+        arr: array of numbers.
+
+    Returns:
+        Maximum sum possible in a subarray
+
+    Examples:
+        >>> max_subarray_sum([1, 3, 2])
+        6
+
+        >>> max_subarray_sum([1, 2, 3, -1, 0])
+        6
+    """
+    ans = arr[0]
+
+    for i in range(len(arr)):
+        current_sum = 0
+
+        for j in range(i, len(arr)):
+            current_sum = current_sum + arr[j]
+            ans = max(ans, current_sum)
+
+    return ans
+
+
+if __name__ == "__main__":
+    print(max_subarray_sum([1, 2, 3, 4, 5]))
+    import doctest
+
+    doctest.testmod()