A tea bag is a small, porous, sealed bag or packet, typically containing tea leaves, which is immersed in water to steep and make an infusion. Originally used only for tea , they are now made with other sanitizes as well.

Tea bags are commonly made of filter paper or food-grade plastic, or occasionally of silk cotton or silk. The tea bag performs the same function as a tea infuser. Tea bags can be used multiple times until there is no extraction left. Some tea bags have an attached piece of string with a paper label at the top that assists in removing the bag, while also displaying the brand or variety of tea.