diff --git a/Mini-Projects/Python/to-do-list-app-gui.py b/Mini-Projects/Python/to-do-list-app-gui.py
new file mode 100644
index 00000000..41bb8cbc
--- /dev/null
+++ b/Mini-Projects/Python/to-do-list-app-gui.py
@@ -0,0 +1,55 @@
+import tkinter as tk
+from tkinter import messagebox
+
+# Functionality to add tasks
+def add_task():
+    task = entry_task.get()
+    if task != "":
+        listbox_tasks.insert(tk.END, task)
+        entry_task.delete(0, tk.END)
+    else:
+        messagebox.showwarning("Input Error", "Please enter a task.")
+
+# Functionality to delete selected task
+def delete_task():
+    try:
+        task_index = listbox_tasks.curselection()[0]
+        listbox_tasks.delete(task_index)
+    except:
+        messagebox.showwarning("Selection Error", "Please select a task to delete.")
+
+# Functionality to mark a task as completed
+def mark_done():
+    try:
+        task_index = listbox_tasks.curselection()[0]
+        task = listbox_tasks.get(task_index)
+        listbox_tasks.delete(task_index)
+        listbox_tasks.insert(tk.END, task + " (Completed)")
+    except:
+        messagebox.showwarning("Selection Error", "Please select a task to mark as completed.")
+
+# Setting up the main application window
+window = tk.Tk()
+window.title("To-Do List App")
+
+# Task entry widget
+entry_task = tk.Entry(window, width=35)
+entry_task.pack(pady=10)
+
+# Add task button
+button_add_task = tk.Button(window, text="Add Task", width=40, command=add_task)
+button_add_task.pack(pady=5)
+
+# Listbox to display tasks
+listbox_tasks = tk.Listbox(window, width=40, height=10)
+listbox_tasks.pack(pady=10)
+
+# Buttons to delete or mark tasks as completed
+button_delete_task = tk.Button(window, text="Delete Task", width=40, command=delete_task)
+button_delete_task.pack(pady=5)
+
+button_mark_done = tk.Button(window, text="Mark as Completed", width=40, command=mark_done)
+button_mark_done.pack(pady=5)
+
+# Running the GUI loop
+window.mainloop()