GUI programming in Python involves using a GUI (graphical user interface) library to create applications that have a graphical interface. This allows users to interact with the application using buttons, text boxes, and other graphical elements, rather than just interacting with the program through the command line. Several GUI libraries are available for Python, including Tkinter, PyQt, and Kivy. These libraries provide a range of tools and widgets that can be used to build graphical user interfaces for Python applications.