Balloon modelling or balloon twisting is the shaping of special modelling balloons into almost any given shape, often a balloon animal. People who create balloon animals and other twisted balloon decoration sculptures are called Twisters, Balloon Benders, and Balloon Artists. Twisters often perform in restaurants, at birthday parties, fairs and at public and private events or functions.

Two of the primary design styles are "single balloon modelling", which restricts itself to the use of one balloon per model, and "multiple balloon modelling", which uses more than one balloon. Each style has its own set of challenges and skills, but few twisters who have reached an intermediate or advanced skill level limit themselves to one style or another. Depending on the needs of the moment, they might easily move between the one-balloon or multiple approaches, or they might even incorporate additional techniques such as "weaving" and "stuffing". Modelling techniques have evolved to include a range of very complex moves, and a highly specialized vocabulary has emerged to describe the techniques involved and their resulting creations. Some twisters inflate their balloons with their own lungs, and for many years this was a standard and necessary part of the act. However, many now use a pump of some sort, whether it is a hand pump, an electric pump plugged in or run by a battery pack, or a compressed gas tank containing air or nitrogen. Twisters do not generally fill their creations with helium, as these designs will not usually float anyway. The balloons for twisting are too porous for helium and the designs are generally too heavy for their size for helium to lift.