This thesis describes global supply chains and the impact on sourcing. At the very beginning, the concept of supply chain is described because it is a key link in every company. Then follows a part of the paper in which sourcing is described in detail, and since there are several types of sourcing, all types are briefly described. Sourcing deals with the actual construction and management of the business entity's supply chain. The concept of sourcing is followed by the concept of procurement. Procurement is one of the fundamental functions of every company. A well-executed procurement process provides the business entity with the establishment of consistent and predictable supply chains. Global supply chains encompass the flow of information, processes, and resources around the world. In the empirical part of the paper, four global brands, two fashion brands and two sports brands are described. All four brands achieve enviable success in the world and set new trends in the world of fashion and sports. The fashion brands selected and compared in the paper are Zara and H&M, and the sports brands selected are Nike and Adidas. The brands were chosen due to their great popularity in the world and to show and explain their business and supply chain in more detail. Each of these brands operates in a specific way and shows the world that there is not only one correct way of doing business, but that good planning and good control of the supply chain is the key to success.