A retort ring is a laboratory tool used to support glassware, such as flasks and test tubes, over a heat source. It consists of a circular metal ring with a raised lip that helps to hold the glassware in place. The ring can be attached to a ring stand or tripod and is typically used in conjunction with a clamp, such as a retort clamp, to provide additional stability and security during heating or other laboratory processes.

Retort rings are commonly used in chemistry, biology, and other sciences, and are known for their durability, stability, and versatility. They are made of materials such as iron, stainless steel, or aluminum, and can be easily cleaned and reused.