A leak-proof, interlocking, stackable travel container assembly has a sealing plug and a plurality of travel containers. The sealing plug is designed to create an airtight seal when positioned within an opening. In order to do so, the sealing plug has a first sealing ring, a second sealing ring and a lip. Each of the plurality of travel containers has a neck portion, an opening, a body portion and a base portion. The opening perpendicularly traverses into the neck portion allowing an user to place and remove items within the travel container. When required, the sealing plug is placed within the opening. Next, a protective cap is used to surround the sealing plug. If multiple travel containers are to be used, a base interlocking mechanism and a neck interlocking mechanism are used for interlocking each of the plurality of travel containers.